WO2021161829A1

WO2021161829A1 - Head-up display device, head-up display system, phase difference film, and laminated glass for vehicle

Info

Publication number: WO2021161829A1
Application number: PCT/JP2021/003464
Authority: WO
Inventors: 洋貴中村; 健介泉谷; 直也森; 晃史奥田
Original assignee: セントラル硝子株式会社
Priority date: 2020-02-13
Filing date: 2021-02-01
Publication date: 2021-08-19
Also published as: CN115066645A; JPWO2021161829A1

Abstract

A polarizing part (81) is provided between a video unit (31) for radiating projection light (60) and a projection part (laminated glass 10 for a vehicle) on which projection light (61) is projected. The polarizing part (81) transmits light that oscillates in a specific direction and that is included in the projection light (60), and the projection light (61) transmitted through the polarizing part (81) is projected to the projection part. The specific direction in which the projection light (60) is transmitted in the polarizing part (81) is parallel to an incidence plane. In this case, the present invention can be used as a P-HUD-type head-up display device. By adjusting the oscillation direction of the light transmitted by the polarizing part, the occurrence of a double image can be suppressed when an observer views an image displayed in a region near the outer periphery of a windshield surface or the central region of the windshield surface from an angle.

Description

Head-up display devices, head-up display systems, retardation films and laminated glass for vehicles

The present disclosure relates to head-up display devices, head-up display systems, retardation films and laminated glass for vehicles.

A windshield installed in the front part of the moving body is used as a projection part of the head-up display (hereinafter, may be referred to as HUD) device. The occupant visually recognizes a virtual image based on the reflected image of the projected light in the projection unit. In the projection unit, reflection images can be formed on both the indoor main surface and the outdoor main surface.

The formation of the reflected image on both the indoor side main surface and the outdoor side main surface in the projection unit is a virtual image that can be visually recognized by the occupant as a double image (the mechanism for generating the double image is Non-Patent Document 1). Please refer to). As a method of suppressing the double image in the HUD device, there are a wedge HUD method and a polarized HUD method.

In the wedge HUD method, the projection portion is provided with a wedge angle profile whose thickness gradually fluctuates, so that a virtual image based on a reflection image formed on the indoor main surface and an outdoor main surface when viewed from the occupant The optical path of the projected light is adjusted so as to match the virtual image based on the reflected image formed in (see Non-Patent Document 1 for the mechanism of double image suppression).

Patent Document 1 discloses a polarized HUD type HUD device.
In the polarized HUD method, the occupant visually recognizes a virtual image display based on the reflected image of the projected light of S-polarized light or P-polarized light in the projection unit. Here, S-polarized light refers to projected light whose vibration direction is perpendicular to the incident surface, while P-polarized light refers to projected light whose vibration direction is parallel to the incident surface.

In this HUD device, the double image of the reflected image, that is, the double image of the virtual image display is suppressed by the following mechanism. The projection unit includes a first glass plate arranged on the outdoor side, a second glass plate arranged on the indoor side, and a retardation film arranged between the first glass plate and the second glass plate. , Each material of the laminated member shall be adjusted so that the refractive index in the visible light region becomes the same. Then, the projected light including the above-mentioned S-polarized light or P-polarized light is incident on the projection unit at Brewster's angle.

When the incident projected light is composed of S-polarized light, a reflected image is formed on the indoor main surface of the second glass plate. Then, the projected light passing through the projection unit is P-polarized by the retardation film. When the P-polarized light reaches the outdoor main surface of the first glass plate, it is emitted to the outdoor side without being reflected by the main surface. The occupant visually recognizes a virtual image display based on the reflected image of S-polarized light formed on the main surface of the second glass plate on the indoor side. This case is referred to as S-HUD.

Further, when the incident projected light is composed of P-polarized light, the ratio of the projected light reflected on the indoor main surface of the second glass plate is low. The projected light passing through the projection unit is S-polarized by the retardation film. When the S-polarized light reaches the outdoor main surface of the first glass plate, a part of it is reflected by the main surface and the rest is emitted from the outdoor side. Since the projected light forming this reflected image passes through the retardation film of the projection unit again, it changes to P-polarized light. The occupant visually recognizes a virtual image display by P-polarized light based on the reflected image formed on the outdoor main surface of the first glass plate. This case is referred to as P-HUD.

International Publication No. 2019/2446919 Japanese Unexamined Patent Publication No. 2000-249966

In recent years, there has been a demand for diversification of information displayed on HUD devices. For example, there is an application of displaying information marking a sign or a pedestrian to assist driving. There is also a request to share image information between the driver's seat and the passenger seat. Information to be shared includes information displayed by the car navigation system and information such as the weather.

In this way, in order to meet the purpose of diversifying the information displayed by the HUD device, it is not enough to display the information only in front of the driver, and it is not enough to display the information only in front of the driver, for example, in an area other than the front of the driver. It may be necessary to display information in an area closer to the outer periphery of the windshield surface than in the front, or in an area between the passenger seat and the driver.

When a virtual image is displayed in the polarized HUD method as in Patent Document 1, the optical axis of the retardation film and the projected light are displayed with the image displayed in front of the viewer who is the occupant who visually recognizes the information by the HUD. The angle formed by the vibration direction is adjusted to suppress the generation of double images.

Patent Document 2 cites a problem that when a large area display is attempted in the polarized HUD method, it becomes difficult to inject the display light at the Brewster's angle over the entire display area, and the large area display cannot be performed. ing.
Then, it is described that the deviation of the Brewster angle due to the increase in area can be solved by changing the wedge angle.

Patent Document 2 describes that the thickness of the front laminated glass is reduced from the position where the optical rotation film is inserted toward the lower side, and the change in the thickness is adjusted by the thickness of the optical rotation film to be inserted. Then, according to this method, it is said that the display area can be expanded by displaying the reflected image at the portion where the optical rotation film is inserted and the lower portion thereof.

However, the expansion of the display area by this method is limited to the portion where the optical rotation film is inserted and the lower portion thereof, and is limited to the method of expanding the display area in the vertical direction of the windshield surface.
Further, reducing the thickness of the front laminated glass in the lower side direction has a demerit that the labor in the manufacturing process increases.

When the occupant sits on the driver's seat side and the passenger's seat side of the moving body and displays the image by HUD in the central area of the windshield surface, the display area of the image is oblique from either of the two occupants (viewers). It becomes the direction.
In such a case, even if the head-up display device is designed so as to suppress the generation of a double image with respect to the image displayed in front of each viewer by the polarized HUD method, the viewer is in an oblique direction. In order to see the image of, both of the two viewers may see the image as a double image.

Based on the above, the present disclosure can suppress the generation of a double image when the viewer visually recognizes the image displayed in the region near the outer periphery of the windshield surface or the central region of the windshield surface from an angle. It provides a head-up display device.

The head-up display device according to the first aspect of the first embodiment of the present disclosure is mounted on a moving body and recognizes a virtual image based on a reflected image at a projection unit of the projected light to a viewer who is an occupant of the moving body. It is a head-up display device that lets you
The X-axis is the direction horizontal to the ground and orthogonal to the traveling direction when the moving body moves forward, the Y-axis is the traveling direction horizontal to the ground and when the moving body moves forward, and the Z-axis is the direction perpendicular to the ground. ,
When the plane having the viewpoint of the viewer, the emission point of the projected light, and the reflection point which is the point where the projected light is reflected is defined as the incident surface,
The head-up display device is
The image unit that irradiates the projected light and
A polarizing unit provided between the image unit and the projection unit to transmit light contained in the projection light that vibrates in a specific direction,
The projection unit, which projects the projected light transmitted through the polarization unit, is provided.
The projection unit is a laminated glass arranged in the order of a second glass plate, a retardation film, and a first glass plate from the indoor side, which is the incident side of the projected light, to the outdoor side.
It has a viewer front region that is the front of the viewer and a viewer oblique front region that is a region farther than the viewer front region along any direction in the X-axis direction.
The projected light is projected onto at least the area diagonally forward to the viewer.
When the X-axis when the projection unit is viewed from the viewer is 0 ° and the plane along the retardation film is the projection plane,
_{The retardation film has an optical axis inclined by θ r with} respect to the X axis on the projection surface, and changes the vibration direction of the projected light incident on the projection surface by the optical axis.
The specific direction is a direction parallel to the incident surface.

In the head-up display device according to the first aspect of the first embodiment of the present disclosure, a polarizing unit is provided between an image unit that irradiates the projected light and a projection unit on which the projected light is projected.
The polarizing unit transmits light contained in the projected light that vibrates in a specific direction, and the projected light transmitted through the polarizing unit is projected onto the projection unit.
The specific direction in which the projected light is transmitted in the polarizing portion is the direction parallel to the incident surface. In this case, it can be used as a P-HUD type head-up display device.
This heads-up display device is suitable for use in sunglasses mode with polarized sunglasses.
By adjusting the vibration direction of the light transmitted by the polarizing part, when the viewer visually recognizes the image displayed in the region near the outer circumference of the windshield surface or the central region of the windshield surface from an angle, a double image is displayed. Can be suppressed.

Further, in the head-up display device according to the first aspect of the first embodiment of the present disclosure, the viewer observes a virtual image based on a reflection image formed on a surface other than the indoor side surface of the second glass plate. It is preferable to do so.
In the head-up display device of the present disclosure, it is preferable that the viewer observes a virtual image based on a reflection image formed on the outdoor surface of the first glass plate.

Further, the head-up display device according to the second aspect of the first embodiment of the present disclosure is mounted on a moving body, and a virtual image based on the reflected image at the projection unit of the projected light is displayed by a viewer who is an occupant of the moving body. It is a head-up display device that makes people recognize
The X-axis is the direction horizontal to the ground and orthogonal to the traveling direction when the moving body moves forward, the Y-axis is the traveling direction horizontal to the ground and when the moving body moves forward, and the Z-axis is the direction perpendicular to the ground. ,
When the plane having the viewpoint of the viewer, the emission point of the projected light, and the reflection point which is the point where the projected light is reflected is defined as the incident surface,
The head-up display device is
The image unit that irradiates the projected light and
A polarizing unit provided between the image unit and the projection unit to transmit light contained in the projection light that vibrates in a specific direction,
The projection unit, which projects the projected light transmitted through the polarization unit, is provided.
The projection unit is a laminated glass arranged in the order of a second glass plate, a retardation film, and a first glass plate from the indoor side, which is the incident side of the projected light, to the outdoor side.
It has a viewer front region that is the front of the viewer and a viewer oblique front region that is a region farther than the viewer front region along any direction in the X-axis direction.
The projected light is projected onto at least the area diagonally forward to the viewer.
When the X-axis when the projection unit is viewed from the viewer is 0 ° and the plane along the retardation film is the projection plane,
_{The retardation film has an optical axis tilted θ r with} respect to the X axis on the projection surface, and the _{angle formed by the vibration direction θ α of the} projected light incident on the projection surface and the optical axis is dθ. In this case, the vibration direction of the incident projected light is rotated by 2dθ.
The vibration direction θ _α is characterized in that it is in the direction of _{2θ r} − θ _{p on} the projection surface when the angle of the incident surface with respect to the X axis on the projection surface is θ _p.

In the head-up display apparatus according to the second aspect of the first embodiment of the present disclosure, and the vibration direction of the projection light incident on the projection plane theta _alpha, the angle at which the optical axis is inclined retardation film with respect to the X axis When θ _r is set and the angle of the incident surface with respect to the X axis on the projection surface is θ _p , the vibration direction θ _α is the direction of 2 θ _r − θ _{p on} the projection surface.
When the vibration direction of the projected light incident on the projection surface satisfies the above conditions, it can be used as an S-HUD type head-up display device. Unlike the P-HUD system, the S-HUD system head-up display device does not distort the image in rainy weather, so that the image can be displayed clearly.
Further, when projecting in an oblique direction, for example _{, the direction of 2θ r} − θ _p _{when θ r} = 45 ° is not orthogonal to the incident surface.

In the head-up display device according to the second aspect of the first embodiment of the present disclosure, it is preferable that the viewer observes a virtual image based on the reflected image formed on the indoor side surface of the second glass plate.

In the head-up display device according to the first embodiment of the present disclosure, there are a plurality of the viewers, and for each of the viewers, the polarizing portion is provided between the video unit and the projection unit. It is preferable that each of the incident surfaces, which is an incident surface provided for each viewer, transmits the projected light vibrating in the specific direction corresponding to each of the incident surfaces.
Further, it is preferable that the polarizing portion has a transmission axis in which the vibration direction of the transmitted projected light is the specific direction, and the directions of the transmission axes are different from each other.
Further, the projected light is in the central region which is between the front area of each of the plurality of viewers and corresponds to the diagonally forward region of each of the plurality of viewers. It is preferably projected.

A polarizing unit is provided for each of a plurality of viewers, and the vibration direction of the projected light transmitted through the polarizing unit is adjusted according to the relationship between the positions of the incident surface and the projection surface provided for each viewer. .. As a result, when a plurality of viewers view the image displayed in the central region of the windshield surface at an angle, the head-up display device can suppress the generation of a double image from any of the viewers. be able to.

In the head-up display device according to the first embodiment of the present disclosure, the projection position on which the projected light is projected can be changed in the projection unit.
It is preferable that the polarizing portion is movable and the vibration direction of the light transmitted through the polarizing portion can be changed in response to the change of the incident surface accompanying the change of the projection position.
When the projection position is changed, the incident surface is changed. If the polarizing portion can be moved in response to a change in the incident surface to change the vibration direction of the light transmitted through the polarizing portion, the double image can be suppressed even if the projection position is changed.

The head-up display system according to the first embodiment of the present disclosure is mounted on a moving body, and a virtual image based on a reflected image at a projection unit of projected light is visually recognized by a viewer who is an occupant of the moving body. It ’s a do-up display system.
The X-axis is the direction horizontal to the ground and orthogonal to the traveling direction when the moving body moves forward, the Y-axis is the traveling direction horizontal to the ground and when the moving body moves forward, and the Z-axis is the direction perpendicular to the ground. ,
When the plane having the viewpoint of the viewer, the emission point of the projected light, and the reflection point which is the point where the projected light is reflected is defined as the incident surface,
The above head-up display system
The image unit that irradiates the projected light and
A polarizing unit provided between the image unit and the projection unit to transmit light contained in the projection light that vibrates in a specific direction,
The projection unit on which the projected light is projected is provided.
The projection unit is a laminated glass arranged in the order of a second glass plate, a retardation film, and a first glass plate from the indoor side, which is the incident side of the projected light, to the outdoor side.
It has a viewer front region that is the front of the viewer and a viewer oblique front region that is a region farther than the viewer front region along any direction in the X-axis direction.
The projected light is projected onto at least the area diagonally forward to the viewer.
When the X-axis when the projection unit is viewed from the viewer is 0 ° and the plane along the retardation film is the projection plane,
_{The retardation film has an optical axis inclined by θ r with} respect to the X axis on the projection surface, and changes the vibration direction of the projected light incident on the projection surface by the optical axis.
The polarizing portion is movable, and the following (A) and (B) can be switched by changing the vibration direction of the light transmitted through the polarizing portion.
(A) The vibration direction of the light incident on the second glass plate is set to be a direction parallel to the incident surface.
(B) the retardation film, when the angle between the vibration direction theta _alpha and the optical axis of the projection light incident on the projection plane and d [theta], thereby 2dθ rotational vibration direction of the projection light incident Assuming that, the vibration direction of the light transmitted through the second glass plate is the direction _{of 2θ r} − θ _{p on} the projection surface when _{the angle of the incident surface with respect to the X axis on the projection surface is θ p.} To be.

In the head-up display system according to the first embodiment of the present disclosure, the polarizing portion is movable, and the vibration direction of the light transmitted through the polarizing portion can be changed. This makes it possible to switch between the S-HUD method and the P-HUD method.
This makes it possible to obtain a head-up display system having a plurality of types of double image suppression methods.

In the head-up display system according to the first embodiment of the present disclosure, the projection position on which the projected light is projected can be changed in the projection unit.
It is preferable that the polarizing portion is movable and the vibration direction of the projected light transmitted through the polarizing portion can be changed in response to the change of the incident surface accompanying the change of the projection position.
When the projection position is changed, the incident surface is changed. If the polarizing portion can be moved in response to a change in the incident surface to change the vibration direction of the projected light transmitted through the polarizing portion, the double image can be suppressed even if the projection position is changed.

The head-up display device according to the first aspect of the second embodiment of the present disclosure is
A head-up display device mounted on a moving body that allows a viewer who is an occupant of the moving body to visually recognize a virtual image based on a reflected image at a projection unit of projected light.
The X-axis is the direction horizontal to the ground and orthogonal to the traveling direction when the moving body moves forward, the Y-axis is the traveling direction horizontal to the ground and when the moving body moves forward, and the Z-axis is the direction perpendicular to the ground. ,
When the plane having the viewpoint of the viewer, the emission point of the projected light, and the reflection point which is the point where the projected light is reflected is defined as the incident surface,
The head-up display device is
The image unit that irradiates the projected light whose vibration direction is the X-axis direction,
A projection unit on which the projected light is projected is provided.
The projection unit is arranged in the traveling direction when the moving body moves forward, and is arranged on the incident side of the projected light and the emitting side of the projected light. It is composed of a laminated glass provided with a first glass plate, a retardation film arranged between the second glass plate and the first glass plate.
The first glass plate includes a first main surface exposed to the outdoor side and a second main surface opposite to the first main surface.
The second glass plate includes a fourth main surface exposed to the indoor side and a third main surface opposite to the fourth main surface.
By making the projected light incident on the retardation film, the vibration direction of the projected light can be converted into a direction parallel to the incident surface.
The projection unit has a viewer front region that is the front of the viewer and a viewer oblique front region that is a region that is far from the viewer front region along any direction in the X-axis direction. death,
When the viewer sees the reflected image formed in the front area of the viewer, the retardation film arranged in the front area of the viewer is a plane parallel to the fourth main surface of the retardation film. The optical axis is 45 ° ± 5 ° with respect to the X axis.
When the viewer sees the reflected image formed in the diagonally front region of the viewer, the retardation film arranged in the diagonally front region of the viewer has the phase difference on a plane parallel to the fourth main surface. The optical axis of the film is tilted from 45 ° ± 5 ° with respect to the X axis.
The imaginary image is based on a reflection image formed on the fourth main surface of the second glass plate.
In both the front area of the viewer and the diagonally front area of the viewer, the light emitted from the first main surface of the first glass plate mainly vibrates in the direction parallel to the incident surface. It is characterized by being.

In the description of the second embodiment of the present disclosure, among the lines connecting the viewpoint of the viewer and the projection portion, the length of the line along the Y axis (distance from the viewpoint to the projection portion) is set to 1000 mm, and the above-mentioned Y axis is set. When the line along the line is 0 °, the range of ± 10 ° along the X-axis direction is defined as the front view area of the viewer.
An area far from the front area of the viewer along any direction in the X-axis direction with respect to the front area of the viewer is defined as an oblique front area of the viewer.

In the head-up display device according to the first aspect of the second embodiment of the present disclosure, when viewing a reflected image formed in the front area of the viewer, which is the front of the viewer, the head-up display device is parallel to the fourth main surface. The optical axis of the retardation film is 45 ° ± 5 ° with respect to the X axis. In the front region of the viewer, the projected light is almost S-polarized. In the front region of the viewer, the projected light (S-polarized light) incident on the retardation film is highly efficiently converted to P-polarized light, so that the generation of double images is suppressed.

When observing a reflection image formed in a region diagonally forward to the viewer, which is a region far from the front region of the viewer, along any direction in the X-axis direction, in a plane parallel to the fourth main surface. The optical axis of the retardation film is tilted in a direction deviated from 45 ° ± 5 ° with respect to the X axis.
Of the light that has passed through the retardation film, the direction of the optical axis of the retardation film is tilted in a direction that deviates from the X-axis by 45 ° ± 5 ° to correspond to the change in the incident surface of the projected light. Improve the proportion of light that oscillates in the direction parallel to the incident surface. As a result, the efficiency of converting the projected light incident on the retardation film into P-polarized light is increased even in the region diagonally forward to the viewer, so that the generation of double images is suppressed.
Since the efficiency of converting the projected light incident on the retardation film into P-polarized light is high in both the front area of the viewer and the diagonally front area of the viewer, the generation of double images is suppressed.
As a result, it is possible to provide a head-up display device capable of suppressing the generation of a double image even when the display area of the HUD is expanded in the lateral direction of the windshield surface.

Further, the head-up display device according to the second aspect of the second embodiment of the present disclosure is mounted on the moving body, and a virtual image based on the reflected image at the projection unit of the projected light is displayed by a viewer who is an occupant of the moving body. It is a head-up display device that allows you to see
The X-axis is the direction horizontal to the ground and orthogonal to the traveling direction when the moving body moves forward, the Y-axis is the traveling direction horizontal to the ground and when the moving body moves forward, and the Z-axis is the direction perpendicular to the ground. ,
When the plane having the viewpoint of the viewer, the emission point of the projected light, and the reflection point which is the point where the projected light is reflected is defined as the incident surface,
The head-up display device is
The image unit that irradiates the projected light whose vibration direction is parallel to the YZ plane,
A projection unit on which the projected light is projected is provided.
The projection unit is arranged in the traveling direction when the moving body moves forward, and is arranged on the incident side of the projected light and the emitting side of the projected light. It is composed of a laminated glass provided with a first glass plate, a retardation film arranged between the second glass plate and the first glass plate.
The first glass plate includes a first main surface exposed to the outdoor side and a second main surface opposite to the first main surface.
The second glass plate includes a fourth main surface exposed to the indoor side and a third main surface opposite to the fourth main surface.
By making the projected light incident on the retardation film, the vibration direction of the projected light can be converted into a direction perpendicular to the incident surface.
The projection unit has a viewer front region that is the front of the viewer and a viewer oblique front region that is a region that is far from the viewer front region along any direction in the X-axis direction. death,
When the viewer sees the reflected image formed in the front area of the viewer, the retardation film arranged in the front area of the viewer is a plane parallel to the fourth main surface of the retardation film. The optical axis is 45 ° ± 5 ° with respect to the X axis.
When the viewer sees the reflected image formed in the diagonally front region of the viewer, the retardation film arranged in the diagonally front region of the viewer has the phase difference on a plane parallel to the fourth main surface. The optical axis of the film is tilted from 45 ° ± 5 ° with respect to the X axis.
The imaginary image is based on a reflection image formed on the first main surface of the first glass plate.
In both the front area of the viewer and the diagonally front area of the viewer, the light reflected by the first main surface of the first glass plate is the projected light that vibrates mainly in the direction perpendicular to the incident surface. It is characterized by being.

This heads-up display device can also be used in sunglasses mode, which uses polarized sunglasses.
In this head-up display device, when viewing a reflected image formed in the front area of the viewer, which is the front of the viewer, the optical axis of the retardation film is 45 with respect to the X axis in a plane parallel to the fourth main surface. It is ° ± 5 °. In the front region of the viewer, the projected light is almost P-polarized. In the front region of the viewer, the projected light (P-polarized light) incident on the retardation film is highly efficiently converted to S-polarized light, so that a virtual image display based on the reflected image formed on the first main surface of the first glass plate can be displayed. Become stronger. Therefore, the influence of the projected light reflected on the fourth main surface is relatively weakened, and the generation of the double image is suppressed.

When observing a reflection image formed in a region diagonally forward to the viewer, which is a region far from the front region of the viewer, along any direction in the X-axis direction, in a plane parallel to the fourth main surface. The optical axis of the retardation film is tilted in a direction deviated from 45 ° ± 5 ° with respect to the X axis.
By tilting the direction of the optical axis of the retardation film in a direction that deviates from the X-axis by 45 ° ± 5 °, the light that has passed through the retardation film can be used in response to changes in the incident surface of the projected light. Improve the proportion of light that oscillates perpendicular to the incident surface. As a result, the virtual image display based on the reflected image formed on the first main surface of the first glass plate becomes stronger even in the area diagonally forward to the viewer. Therefore, the influence of the projected light reflected on the fourth main surface is relatively weakened, and the generation of the double image is suppressed.
Since the efficiency of converting the projected light incident on the retardation film into S-polarized light is high in both the front area of the viewer and the diagonally front area of the viewer, the generation of double images is suppressed.
As a result, it is possible to provide a head-up display device capable of suppressing the generation of a double image even when the display area of the HUD is expanded in the lateral direction of the windshield surface.

In the head-up display device according to the second embodiment of the present disclosure, the right peripheral area located on the right side of the viewer front area and the left side located on the left side of the viewer front area in the viewer oblique front area. In the peripheral region, it is preferable that the direction in which the optical axis of the retardation film deviates from the X axis by 45 ° ± 5 ° is opposite.
By defining in this way, it is possible to suppress the generation of double images on both the left and right sides of the viewer.

In the head-up display device according to the second embodiment of the present disclosure, the inclination of the retardation film in the direction of the optical axis in the area diagonally forward to the viewer is continuously changed along the X-axis direction. Is preferable.
Further, it is preferable that the change in the inclination of the retardation film in the direction of the optical axis in the diagonally forward region of the viewer is discontinuous along the X-axis direction.

Further, the retardation film according to the second embodiment of the present disclosure is an integral retardation film having a vertical axis in the vertical direction and a horizontal axis in the horizontal direction.
At a plurality of points along the vertical axis, the angle formed by the optical axis of the retardation film and the horizontal axis is constant.
Along the horizontal axis direction, the angle formed by the optical axis of the retardation film and the horizontal axis changes with a constant tendency.

By arranging such a retardation film so that the lateral direction of the windshield and the lateral axis direction of the retardation film are aligned, it is possible to provide a HUD device having a wide display area in the lateral direction of the windshield surface.

In the retardation film according to the second embodiment of the present disclosure, it is preferable that the angle formed by the optical axis of the retardation film and the horizontal axis continuously changes along the horizontal axis direction.
Further, it is preferable that the angle formed by the optical axis of the retardation film and the horizontal axis changes discontinuously along the horizontal axis direction.

Further, the laminated glass for a vehicle according to the second embodiment of the present disclosure is a retardation film arranged between the first glass plate, the second glass plate, and the first glass plate and the second glass plate. It is a laminated glass for vehicles equipped with
The retardation film is the retardation film according to the second embodiment of the present disclosure.

By using such a laminated glass for vehicles, it is possible to provide a HUD device having a wide display area in the lateral direction of the windshield surface.

The head-up display system according to the second embodiment of the present disclosure is mounted on a moving body, and a head-up that allows a viewer who is an occupant of the moving body to visually recognize a virtual image based on a reflected image at a projection unit of projected light. It ’s a display system,
The X-axis is the direction horizontal to the ground and orthogonal to the traveling direction when the moving body moves forward, the Y-axis is the traveling direction horizontal to the ground and when the moving body moves forward, and the Z-axis is the direction perpendicular to the ground. ,
When the plane having the viewpoint of the viewer, the emission point of the projected light, and the reflection point which is the point where the projected light is reflected is defined as the incident surface,
The above head-up display system
The image unit that irradiates the projected light and
A projection unit on which the projected light is projected is provided.
The projection unit is arranged in the traveling direction when the moving body moves forward, and is arranged on the incident side of the projected light and the emitting side of the projected light. It is composed of a laminated glass provided with a first glass plate, a retardation film arranged between the second glass plate and the first glass plate.
The first glass plate includes a first main surface exposed to the outdoor side and a second main surface opposite to the first main surface.
The second glass plate includes a fourth main surface exposed to the indoor side and a third main surface opposite to the fourth main surface.
By making the projected light incident on the retardation film, the vibration direction of the projected light can be converted into a direction parallel to or perpendicular to the incident surface.
The projection unit has a viewer front region that is the front of the viewer and a viewer oblique front region that is a region that is far from the viewer front region along any direction in the X-axis direction. death,
When the viewer sees the reflected image formed in the front area of the viewer, the retardation film arranged in the front area of the viewer is a plane parallel to the fourth main surface of the retardation film. The optical axis is 45 ° ± 5 ° with respect to the X axis.
When the viewer sees the reflected image formed in the diagonally front region of the viewer, the retardation film arranged in the diagonally front region of the viewer has the phase difference on a plane parallel to the fourth main surface. The optical axis of the film is tilted from 45 ° ± 5 ° with respect to the X axis.
The image unit can switch between the first projected light whose vibration direction is the X-axis direction and the second projected light whose vibration direction is parallel to the YZ plane.
When the viewer visually recognizes the virtual image without passing through the polarizing plate, the first projected light is irradiated from the image unit, and the virtual image is formed on the fourth main surface of the second glass plate. Based on the reflected image, the light emitted from the first main surface of the first glass plate is mainly in the direction parallel to the incident surface in both the front area of the viewer and the oblique front area of the viewer. It is a vibrating projected light,
When the viewer visually recognizes the virtual image through the polarizing plate, the second projected light is irradiated from the image unit, and the virtual image is a reflection formed on the first main surface of the first glass plate. Based on the image, the light reflected by the first main surface of the first glass plate vibrates mainly in the direction perpendicular to the incident surface in both the front area of the viewer and the obliquely front area of the viewer. It is characterized in that it is a projected light.

The head-up display system according to the second embodiment of the present disclosure has a sunglasses mode in which a virtual image is visually recognized through a polarizing plate such as polarized sunglasses by switching between two types of projected light emitted from an image unit, and a polarizing plate. It is possible to switch and use the normal mode for visually recognizing a virtual image without going through it.
Then, when the display area of the HUD is expanded in the lateral direction of the windshield surface, the generation of the double image can be suppressed in any mode.

According to the present disclosure, a head-up display device capable of suppressing the generation of a double image when a viewer visually recognizes an image displayed in a region near the outer periphery of the windshield surface or a central region of the windshield surface from an angle. Can be provided.

FIG. 1 is a top view of a moving body including a HUD device. FIG. 2 is a view of a laminated glass for a vehicle used in the HUD device as viewed from the fourth main surface side. FIG. 3 is an exploded perspective view schematically showing an example of laminated glass for a vehicle. FIG. 4 is a schematic view showing an outline of a first HUD device according to a first aspect of the first embodiment of the present disclosure and an optical path in the device. FIG. 5 is a schematic view showing an outline of a second HUD device according to a second aspect of the first embodiment of the present disclosure and an optical path in the device. FIG. 6 is a schematic diagram for explaining the vibration direction of the light transmitted through the polarizing portion in the second HUD device. FIG. 7 is a diagram schematically showing an example of the relationship between the positions of the viewer and the projection unit and the position of the transmission axis of the polarizing unit in the first HUD device. FIG. 8 is a diagram schematically showing an example of the relationship between the positions of the viewer and the projection unit and the position of the transmission axis of the polarizing unit in the second HUD device. FIG. 9 is a diagram schematically showing an example of the relationship between the positions of the viewer and the projection unit and the position of the transmission axis of the polarizing unit when there are a plurality of viewers in the first HUD device. FIG. 10 is a diagram schematically showing an example of the relationship between the positions of the viewer and the projection unit and the position of the transmission axis of the polarizing unit when there are a plurality of viewers in the second HUD device. FIG. 11 is a layout diagram schematically showing the first HUD apparatus used in Examples and Comparative Examples. FIG. 12 is a diagram schematically showing the experimental system in Example 1. FIG. 13 is a diagram schematically showing the experimental system in Comparative Example 1. FIG. 14 is a photograph showing a virtual image visually recognized in Example 1 and Comparative Example 1. FIG. 15 is a diagram schematically showing the experimental system in Example 2. FIG. 16 is a diagram schematically showing the experimental system in Comparative Example 2. FIG. 17 is a photograph showing a virtual image visually recognized in Example 2 and Comparative Example 2. FIG. 18 is a drawing schematically showing an example of a retardation film according to the second embodiment of the present disclosure. FIG. 19 is a drawing schematically showing an example of another retardation film according to the second embodiment of the present disclosure. FIG. 20 is an exploded perspective view schematically showing an example of a laminated glass for a vehicle according to a second embodiment of the present disclosure. FIG. 21 is a schematic view showing an outline of a third HUD device according to the first aspect of the second embodiment of the present disclosure and an optical path in the device. FIG. 22 is a diagram schematically showing the positions of the viewer front region and the viewer diagonally forward region in a right-hand drive vehicle. FIG. 23 is a diagram schematically showing the positions of the viewer front region and the viewer diagonally forward region in the left-hand drive vehicle. FIG. 24 is a diagram schematically showing another aspect of the positions of the viewer front region and the viewer oblique front region when the driver of the right-hand drive vehicle is a viewer. FIG. 25 is a diagram schematically showing another aspect of the positions of the viewer front region and the viewer oblique front region when the driver of the left-hand drive vehicle is a viewer. FIG. 26 is a diagram schematically showing the positions of the viewer front region and the viewer oblique front region when there are two viewers, the driver and the passenger seat occupant. FIG. 27 is a diagram schematically showing another aspect of the positions of the viewer front region and the viewer oblique front region when there are two viewers, the driver and the passenger seat occupant. FIG. 28 is a diagram schematically showing a mode in which the projection portion is extended to the side glass. FIG. 29 is a schematic diagram showing an outline of a fourth HUD device according to a second aspect of the second embodiment of the present disclosure and an optical path in the device. FIG. 30 is a layout diagram schematically showing the third HUD device used in Examples and Comparative Examples. FIG. 31 is a diagram schematically showing the experimental system in Example 3. FIG. 32 is a diagram schematically showing the experimental system in Comparative Example 3. FIG. 33 is a photograph showing a virtual image visually recognized in Example 3 and Comparative Example 3. FIG. 34 is a diagram schematically showing the experimental system in Example 4. FIG. 35 is a diagram schematically showing the experimental system in Comparative Example 4. FIG. 36 is a photograph showing a virtual image visually recognized in Example 4 and Comparative Example 4.

(First Embodiment)
The head-up display device (HUD device) and the head-up display system (HUD system) according to the first embodiment of the present disclosure will be described with reference to the drawings.

The HUD device according to the first embodiment of the present disclosure is a HUD device (P-HUD type HUD device) in which a viewer observes a virtual image based on a reflected image formed on a surface other than the indoor side surface of the second glass plate. There are HUD devices (S-HUD type HUD devices) in which the viewer observes a virtual image based on the reflected image formed on the indoor side surface of the second glass plate, and these are the first HUD device and the second HUD, respectively. Also called a device. In the description of the head-up display device according to the first embodiment of the present disclosure, when the first HUD device and the second HUD device are not distinguished, it is simply referred to as the HUD device according to the first embodiment of the present disclosure.
Further, the HUD system according to the first embodiment of the present disclosure can be used as both a first HUD device and a second HUD device by switching the vibration direction of the light transmitted through the polarizing portion in one system. It is a system that enables it.

Further, in the description of the first embodiment of the present disclosure, among the lines connecting the viewpoint of the viewer and the projection portion, the length of the line along the Y axis (distance from the viewpoint to the projection portion) is set to 1000 mm as described above. When the line along the Y-axis is 0 °, the range of ± 3 ° along the X-axis direction is defined as the front area of the viewer. Further, when the range is expanded along the Z-axis direction, it is also defined as the front area of the viewer.
An area far from the front area of the viewer along any direction in the X-axis direction with respect to the front area of the viewer is defined as an oblique front area of the viewer. Further, a region that is far from the viewer front region along the X-axis direction and the Z-axis direction is also defined as a viewer diagonally forward region.
Further, in the description of the first embodiment of the present disclosure, the surface along the retardation film and the surface on which the projected light is incident on the retardation film is referred to as a projection plane. The projection surface is a surface including the main surface of the retardation film.

[Head-up display device (HUD device)]
There are two types of HUD devices according to the first embodiment of the present disclosure, a first HUD device and a second HUD device. First, the definitions of the X-axis, the Y-axis, and the Z-axis, which are common to both HUD devices, and the moving body will be described.
FIG. 1 is a top view of a moving body including a HUD device, and FIG. 2 is a view of a laminated glass for a vehicle used for the HUD device as viewed from the indoor side surface (fourth main surface) side of the second glass plate. ..
The orientations of the X-axis, Y-axis, and Z-axis in the present disclosure will be described with reference to FIGS. 1 and 2.
FIG. 1 shows the vehicle 20 as a moving body, and the X-axis is shown in the horizontal direction and the Y-axis is shown in the vertical direction. The Z axis is in the direction perpendicular to the paper surface.
The Y-axis is the traveling direction when the vehicle 20 which is horizontal to the ground and is a moving body moves forward.
The X-axis is a direction that is horizontal to the ground and orthogonal to the traveling direction (Y-axis) when the moving vehicle 20 moves forward.
The Z axis is perpendicular to the ground.
Further, the direction of the first glass plate when the first glass plate side is viewed from the second glass plate side is defined as "forward".

Examples of the moving body include vehicles (passenger cars, trucks, buses, trains, etc.), trains, ships, airplanes, and the like. Among these, a vehicle is preferable.

FIG. 2 shows a laminated glass 10 for a vehicle. When the laminated glass 10 for a vehicle is installed in a vehicle, its glass surface is not parallel to the XZ plane, and is often arranged at an angle from the XZ plane.

Next, the laminated glass for vehicles will be described.
FIG. 3 is an exploded perspective view schematically showing an example of laminated glass for a vehicle.
The first glass plate includes a first main surface exposed to the outdoor side and a second main surface opposite to the first main surface.
Further, the second glass plate includes a fourth main surface exposed to the indoor side and a third main surface opposite to the fourth main surface.
The above-mentioned "exposed" means that a film, a film, or the like for imparting various functions such as anti-fog property and scratch resistance is placed on each main surface within a range that does not impair the function of the laminated glass for vehicles. You may have it.
FIG. 3 shows a laminated glass 10 for a vehicle.
FIG. 3 shows a view in which the second glass plate 12 is arranged on the front side of the drawing, and the surface visible on the front side is the fourth main surface 124. The surface opposite to the fourth main surface 124 is the third main surface 123.
The first glass plate 11 is arranged on the back side of the drawing, and the surface visible on the front side is the second main surface 112. The surface opposite to the second main surface 112 is the first main surface 111.
A retardation film 100 is arranged between the first glass plate 11 and the second glass plate 12.
Since the fourth main surface 124 is a surface exposed to the indoor side, it is a surface that the viewer can directly see when the laminated glass for the vehicle is arranged on the vehicle. That is, FIG. 3 shows the positional relationship in which the viewer directly sees from the inside of the vehicle.

In the laminated glass for vehicles, it is preferable that the first glass plate and the second glass plate are joined via an interlayer film to form an integral structure. The interlayer film combines the first glass plate and the second glass plate by heating at a temperature at which the polymer constituting the interlayer film softens. As polymers, polyvinyl butyral (PVB) and ethylene acetate are used. Vinyl (EVA), acrylic resin (PMMA), urethane resin, polyethylene terephthalate (PET), cycloolefin polymer (COP) and the like can be used. The interlayer film may be composed of a plurality of resin layers.

As the glass material constituting the laminated glass for vehicles, a flat glass plate processed into a curved shape can be preferably used. As the material of the glass plate, in addition to soda lime silicate glass as specified in ISO16293-1, a glass having a known glass composition such as aluminosilicate glass, borosilicate glass, and non-alkali glass can be used. can. The thickness of each of the first glass plate and the second glass plate may be, for example, 0.4 mm to 3 mm. The distance between the first glass plate and the second glass plate may be 0.01 mm to 2.5 mm.

_{The retardation film 100 has an optical axis inclined by θ r with} respect to the X axis on the projection surface, and the optical axis changes the vibration direction of the projected light incident on the projection surface. For example, when the retardation film is a 1/2 wavelength film, when the vibration direction of the projected light incident on the projection surface and the angle formed by the optical axis are dθ, the vibration direction of the incident projected light is set. Rotate by 2dθ.
In the first embodiment of the present disclosure, the optical axis of the retardation film means the axis in the direction in which the refractive index of the retardation film is the largest. Further, the retardation film may include a layer or a film having no base material. For example, a layer having an optical axis in the projection portion may be formed by coating, laminating, adhering, adhering, crimping, transferring, or the like.

The retardation film is arranged between the first glass plate and the second glass plate.
The retardation film may be arranged inside the interlayer film, may be arranged at a position in contact with the first glass plate, or may be arranged at a position in contact with the second glass plate. Further, as shown in FIG. 3, the surface of the retardation film may be arranged so as to face the second main surface and the third main surface. Further, the retardation film may be arranged on the entire surface or partially, and the total area of the surfaces of the retardation film facing the second main surface or the third main surface is the second main surface or It is preferably equal to or less than the area of the third main surface.
Further, a plurality of retardation films may be used as needed, and different types of retardation films or films other than the retardation films may be used in combination.
By arranging the sides of the laminated glass for vehicles on which the above retardation film is arranged along the X-axis, the laminated glass for vehicles as a windshield can be obtained.

As the retardation film, a retardation element obtained by uniaxially or biaxially stretching a plastic film such as polycarbonate, polyarylate, polyether sulfone, cycloolefin polymer, triacetyl cellulose, polyethylene terephthalate (PET), or polyethylene naphthalate (PEN). Alternatively, a retardation element in which the liquid crystal polymer is oriented in a specific direction and the orientation state is fixed can be used.
As the former phase difference element obtained by stretching a plastic film uniaxially or biaxially, for example, a polymer resin is dissolved in a solvent and then applied on a smooth surface such as a stainless steel belt or polyethylene terephthalate (PET) to evaporate the solvent. The film is formed by a solvent casting method in which the film is wound after being wound, or a melt extrusion method in which a polymer resin is placed in an extruder to be heated and melted, extruded from a slit (T die), cooled, and then the film is wound. Can be used. A stretching machine is generally used for stretching, and a retardation film stretched vertically, horizontally, diagonally, or the like can be obtained.
As the latter retardation element, for example, a liquid crystal polymer is coated on a transparent substrate such as a transparent plastic film such as polyethylene terephthalate (PET) or triacetyl cellulose (TAC) which has been oriented, and heat-treated and cooled to align the liquid crystal. A fixed one can be used.
Examples of the above-mentioned liquid crystal polymer are not particularly limited as long as they are compounds exhibiting liquid crystal properties such as nematic liquid crystal, twisted nematic liquid crystal, discotic liquid crystal, and cholesteric liquid crystal when oriented in a specific direction. For example, those that are twisted and nematically oriented in the liquid crystal state and are in the glass state below the liquid crystal transition point can be used, and can be used as a main chain type liquid crystal polymer such as optically active polyester, polyamide, polycarbonate, polyesterimide, or optically active poly. Examples thereof include side-chain liquid crystal polymers such as acrylate, polymethacrylate, polycarbonate, and polysiloxane. Further, a polymer composition obtained by adding another small molecule or high molecular weight optically active compound to these non-optically active main chain type or side chain type polymers can be exemplified.
The role of the retardation film in each of the first HUD device and the second HUD device will be described later.

[First HUD device]
First, the HUD device according to the first aspect of the first embodiment of the present disclosure will be described by taking the first HUD device as an example.
FIG. 4 is a schematic diagram showing an outline of a first HUD device according to a first aspect of the first embodiment of the present disclosure and an optical path in the device.
In FIG. 4, the optical path of the projected light is shown by a solid line.
In the first HUD device 1, the projection unit is the vehicle laminated glass 10 shown in FIG.

In the first HUD device 1 shown in FIG. 4, the projected light 60 is emitted from the image unit 31.
Here, the plane including the light emitting point 32 of the image unit 31, the reflection point 33 on which the projected light 60 is reflected on the first main surface 111, and the viewpoint 34 of the viewer 35 is the incident surface.

The projected light 60 emitted from the image unit 31 does not need to be limited in the vibration direction, but if the light is P-polarized light whose vibration direction is parallel to the incident surface, the amount of light passing through the polarized light unit 81 is large. Therefore, it is preferable because the amount of light reaching the first main surface can be increased.
In the vehicle, it is preferable that the image unit 31 is arranged on the dashboard or the like of the vehicle.
The position of irradiating the projected light 60 can be moved by changing the direction of irradiating the projected light 60 from the image unit 31 or moving the position of the image unit 31.

A polarizing unit 81 is provided between the image unit 31 and the projection unit (laminated glass 10 for a vehicle). The polarizing unit 81 is a member having a transmission axis in which the vibration direction of the transmitted projected light 60 is a specific direction, and for example, a known polarizing plate or the like can be used.
It is desirable that the above-mentioned polarizing plate has an absorption axis that absorbs light vibrating in the direction perpendicular to the above-mentioned specific direction. With the above-mentioned transmission axis and absorption axis, for example, when light that vibrates in a direction that does not follow either the transmission axis or the absorption axis is incident, the vibration direction of the transmitted light can be set to the above-mentioned specific direction. It will be easy.
The polarizing unit 81 may be arranged at a position where it can pass through the polarizing unit 81 before the projected light 60 reaches the projection unit. For example, in a vehicle, the polarizing unit 81 is arranged in the dashboard in the same manner as the video unit 31 described above, and is arranged adjacent to the light source so that the light from the light source quickly passes through the polarizing unit 81. Is preferable.

In the first HUD device 1, the polarizing unit 81 transmits light vibrating in a direction parallel to the incident surface. That is, the projected light 61 after passing through the polarizing unit 81 becomes P-polarized light.

When the projected light 61 after passing through the polarizing unit 81 is P-polarized, it can also be used in sunglasses mode in which a virtual image is observed through polarized sunglasses. Further, although polarized sunglasses 36 are used in FIG. 4, a virtual image can be observed with the naked eye as a matter of course. First, the projected light 60 emitted from the image unit 31 passes through the polarizing unit 81 and is irradiated on the fourth main surface 124 as the projected light 61 of P-polarized light. The angle at this time is preferably Brewster's angle. In general, P-polarized light incident at Brewster's angle does not cause reflection, so that it is possible to suppress reflection on the fourth main surface 124, which causes a double image.
The image unit can be moved in the X-axis direction and the Y-axis direction so that the angle at which the projected light 61 is applied to the fourth main surface 124 is the Brewster's angle.
Next, when the projected light 61 traveling in the projection unit is incident on the retardation film 100, the vibration direction changes.
In the first HUD device 1, since it is sufficient that reflection occurs on any surface other than the fourth main surface, the retardation film 100 is a 1/2 wavelength film (half wavelength film) or a 1/4 wavelength film. Etc. can be used.
The vibration direction of light after passing through the retardation film 100 varies depending on the type of retardation film and the direction of the optical axis. For example, when a 1/2 wavelength film is used as the retardation film, the projection surface When the angle formed by the vibration direction of the incident projected light and the optical axis of the retardation film is dθ, the vibration direction of the projected light is rotated by 2 dθ.
Next, when the projected light reaches the first main surface 111, it is reflected to form a reflected image. At this time, S-polarized light is reflected as reflected light, and other light that is not reflected passes through the first main surface 111 and is emitted to the outdoor side.
Next, the reflected image formed on the first main surface 111 passes through the retardation film 100 again and becomes P-polarized light. The viewer 35 visually recognizes the virtual image 621 on the extension of the optical path 62 based on the reflected image on the first main surface 111.
Since the virtual image 621 is composed of P-polarized light, the viewer 35 can visually recognize the virtual image 621 even through the polarized sunglasses 36.
In this case, the viewer observes a virtual image based on the reflected image formed on the outdoor side surface (that is, the first main surface) of the first glass plate.

Further, if there is a reflection layer that reflects light before reaching the first main surface 111, reflection occurs in the layer. In that case, if the unreflected light reaches the first main surface 111 and further reflection occurs, this reflection may cause a double image. Therefore, if reflection occurs before reaching the first main surface 111, it is preferable to change the vibration direction of the light so that the light becomes P-polarized again before reaching the first main surface 111.
Including such a case, it is preferable that the viewer observes a virtual image based on the reflected image formed on the side other than the indoor side surface of the second glass plate. The "reflection image formed on the indoor side surface of the second glass plate" also includes the "reflection image formed on the outdoor side surface of the first glass plate".

Further, in the first HUD device, it is preferable that the polarizing unit 81 is movable and the vibration direction of the light transmitted through the polarizing unit 81 can be changed.
When the polarizing unit 81 is movable, when the incident surface changes, the polarizing unit 81 moves so that the specific direction can be aligned with the direction parallel to the incident surface. By aligning the specific direction with the direction parallel to the incident surface, it can be suitably used as a P-HUD type HUD device.

[Second HUD device]
Next, the HUD device according to the second aspect of the first embodiment of the present disclosure will be described by taking the second HUD device as an example.
FIG. 5 is a schematic view showing an outline of a second HUD device according to a second aspect of the first embodiment of the present disclosure and an optical path in the device.
In FIG. 5, the optical path of the projected light is shown by a solid line.
In the second HUD device 2, the projection unit is the vehicle laminated glass 10 shown in FIG.

A polarizing unit 82 is provided between the image unit 31 and the projection unit (laminated glass 10 for a vehicle). The polarizing unit 82 is a member having a transmission axis that transmits light contained in the projected light that vibrates in a specific direction, and for example, a known polarizing plate or the like can be used.
The polarizing unit 82 may be arranged at a position where it can pass through the polarizing unit 82 before the projected light 40 reaches the projection unit. For example, in a vehicle, the polarizing unit 82 is arranged in the dashboard in the same manner as the video unit 31 described above, and is arranged adjacent to the light source so that the light from the light source quickly passes through the polarizing unit 82. Is preferable.

In the second HUD device 2, the polarizing unit 82 transmits light contained in the projected light 40 that vibrates in a specific direction.

In the second HUD device 2, the projected light 40 is emitted from the image unit 31.
The projected light 41 after the projected light 40 has passed through the polarizing portion 82 is irradiated on the fourth main surface 124, and a reflected image is formed on the fourth main surface 124. The viewer 35 observes the virtual image 421 on the extension of the optical path 42 based on the reflected image formed on the fourth main surface 124.

The plane including the light emitting point 32 of the image unit 31, the reflection point 33 on which the projected light 41 is reflected on the fourth main surface 124, and the viewpoint 34 of the viewer 35 is the incident surface.

The direction of vibration of the projected light 40 emitted from the image unit 31 is not particularly limited, but for the purpose of increasing the amount of light that vibrates in a specific direction transmitted through the polarizing unit 82, the polarizing unit 82 It is desirable to include light that oscillates in a direction parallel to the transmission axis.
The projected light that vibrates in a specific direction is a transmitted light that passes through the second glass plate and a reflected light that is reflected on the indoor side surface of the second glass plate. The vibration direction of the projected light that vibrates in a specific direction that has passed through the polarizing portion is the vibration direction θ _{α described} below after passing through the second glass plate.

In the vehicle, the image unit 31 is preferably arranged on the dashboard of the vehicle.
The position of irradiating the projected light 40 can be moved by changing the direction of irradiating the projected light 40 from the image unit 31 or moving the position of the image unit 31.

When a part of the projected light 41 after passing through the polarizing portion 82 is not reflected by the fourth main surface 124 and is transmitted through the fourth main surface 124, the vibration direction of the projected light 41 traveling in the projection portion has a phase difference. It changes by passing through the film 100.
The retardation film 100 has _{an optical axis tilted θ r with} _{respect to the X axis on the projection surface, and the vibration direction θ α} of the projected light 41 that passes through the second glass plate 12 and is incident on the projection surface is projected. When the angle of the incident surface with respect to the X-axis on the surface is θ _p _{, if the direction is 2 θ r} − θ _p on the projected surface, the vibration direction of the projected light is described above by passing through the retardation film 100. In this way, it rotates by 2dθ and becomes a direction parallel to the incident surface, that is, a vibration direction similar to that of P-polarized light.
The change in the vibration direction of the projected light 41 will be described below with reference to the drawings.

FIG. 6 is a schematic diagram for explaining the vibration direction of the light incident on the retardation film 100 in the second HUD device. Further, FIG. 6 shows a case where the viewer looks forward (direction in which the first main surface side is viewed from the fourth main surface side).
In FIG. 6, the X axis is shown as 0 °.
The angle of the optical axis of the retardation film with respect to the X axis is θ _r . Here, θ _r is shown at 45 °.
The vibration direction of P-polarized light is a direction parallel to the incident surface, and the vibration direction of S-polarized light is a direction perpendicular to the incident surface.
Let dθ be the angle formed by the vibration direction of the projected light 41 and the optical axis of the retardation film. When the projected light 41 passes through the retardation film, the vibration direction of the projected light is rotated by 2 dθ. That is, the vibration direction of the projected light 41 rotates 2dθ clockwise or counterclockwise in the drawing. By this rotation, the vibration direction of the projected light 41 is made parallel to the incident surface.
When such a condition is satisfied, the projected light 41 passes through the retardation film and changes to P-polarized light.

The projection light oscillation direction incident on the projection surface such as to satisfy the condition puts a theta _alpha.
θ _α is obtained as follows.
The angle of the incident surface with respect to the X-axis is the angle indicated by _{θ p in FIG.}
From FIG. 6, dθ = θ _p −θ _r . ... Equation (1)
From FIG. 6, θ _α = θ _{r −} dθ. ... Equation (2)
From the above equations (1) and (2), θ _α = 2 _{θ r} −θ _p
Will be.
When the above equation (1) is +, the vibration direction rotates counterclockwise in FIG. 6, and when −, it rotates clockwise.
That is, when the _{projected light 41 satisfying θ α} = 2 _{θ r} −θ _p is incident on the retardation film, the vibration direction of the light after passing through the retardation film becomes parallel to the incident surface.
_{By making the vibration direction θ α} of the projected light satisfy θ _α = 2 _{θ r} −θ _p before the projected light is incident on the retardation film 100, the light in the other vibration directions causing the double image. Is prevented from entering the retardation film.

The projected light that has passed through the retardation film 100 and becomes P-polarized is emitted to the outdoor side as P-polarized light without being reflected by the first main surface 111.
As described above, if it is possible to suppress the reflection of the projected light that was not reflected by the fourth main surface 124 on the first main surface 111, the generation of the double image is suppressed.

Further, in the second HUD device, it is preferable that the polarizing unit 82 is movable and the vibration direction of the light transmitted through the polarizing unit 82 can be changed.
When the polarizing unit 82 is movable, when the incident surface changes, the polarizing unit 82 moves, so that the vibration direction of the light transmitted through the polarizing unit 82 can be changed, and the projected light incident on the projection surface can be changed. The vibration direction θ _α can be adjusted to satisfy θ _α = 2 _{θ r} − θ _p. _{Since the polarizing unit 82 is movable, it becomes easy to adjust the vibration direction θ α} of the projected light incident on the projection surface to the direction _{satisfying θ α} = 2 _{θ r} −θ _p even if the projection position is changed. Therefore, the S-HUD method is used. Can be suitably used as a HUD device of.

[Example of orientation of transmission axis of polarizing part]
Subsequently, an example of the direction of the transmission axis of the polarizing portion in each of the first HUD device and the second HUD device will be described. The HUD device of the present disclosure is not limited to the examples given below.
In the example below, the viewer is seated in the position of the driver of a right-hand drive vehicle.
The front of the viewer is the front area of the viewer, and the area farther than the front area of the viewer along any direction in the X-axis direction is defined as the diagonally front region of the viewer.

FIG. 7 is a diagram schematically showing an example of the relationship between the positions of the viewer and the projection unit and the orientation of the transmission axis of the polarizing unit in the first HUD device.
In FIG. 7, the viewer 35 is seated at the position of the driver of the right-hand drive vehicle.
FIG. 7 shows the orientation of the transmission axis of the image 621L projected on the left side of the viewer 35 in the diagonally forward region of the viewer and the polarizing portion 81L used when viewing the image 621L. Further, it shows the orientation of the transmission axis of the image 621R projected onto the area diagonally forward of the viewer on the right side of the viewer and the polarizing portion 81R used when viewing the image 621R.

When the viewer sees each image, the direction of the transmission axis of the polarizing portion is adjusted.
The direction of the transmission axis of the polarizing portion in FIG. 7 is the direction along the Z axis in the front region of the viewer, and this case is shown as a dotted line in the polarizing portion 81L and the polarizing portion 81R as a reference line.
On the other hand, the transmission axis of the polarizing unit 81L and the polarizing unit 81R is a solid line shown in the polarizing unit 81L and the polarizing unit 81R.
In the case of FIG. 7, for example, in the polarizing portion 81L provided on the left side of the viewer, the transmission axis is rotated counterclockwise on a plane along the XX plane. On the other hand, in the polarizing unit 81R provided on the right side of the viewer, the transmission axis is rotated clockwise. The angle at which the transmission axis is rotated may be adjusted to an angle that minimizes the double image. Further, it is preferable to adjust the transmission axis so that the direction is parallel to the incident surface.
Since the transmission axis is on the Z axis in FIG. 7, the direction along the Z axis direction is used as a reference. However, when the transmission axis is on the X axis as shown in FIG. 8, the direction along the X axis is used. Use as a reference.

FIG. 8 is a diagram schematically showing an example of the relationship between the positions of the viewer and the projection unit and the orientation of the transmission axis of the polarizing unit in the second HUD device.
In FIG. 8, the viewer 35 is seated at the position of the driver of the right-hand drive vehicle.
FIG. 8 shows the orientation of the transmission axis of the image 421L projected on the left side of the viewer 35 in the diagonally forward region of the viewer and the polarizing portion 82L used when viewing the image 421L. Further, the orientation of the transmission axis of the image 421R projected on the right side of the viewer and the obliquely forward region of the viewer and the polarizing portion 82R used when viewing the image 421R is shown.

When the viewer sees each image, the direction of the transmission axis of the polarizing portion is adjusted.
The direction of the transmission axis of the polarizing section in FIG. 8 is the direction along the X axis in the front region of the viewer, and this case is shown as a dotted line in the polarizing section 82L and the polarizing section 82R with this case as a reference line.
On the other hand, the transmission axes of the polarizing section 82L and the polarizing section 82R are solid lines shown in the polarizing section 82L and the polarizing section 82R.
In the case of FIG. 8, for example, in the polarizing portion 82L provided on the left side of the viewer, the transmission axis is rotated clockwise on a plane along the XX plane. On the other hand, in the polarizing unit 82R provided on the right side of the viewer, the transmission axis is rotated counterclockwise.
The angle at which the transmission axis is rotated may be adjusted to an angle that minimizes the double image.

Although FIGS. 7 and 8 show an example when the optical axis of the retardation film is 45 °, the direction in which the transmission axis is rotated may be opposite to the above-described direction depending on the angle of the optical axis. However, it may be possible to suppress the double image more.

[Arbitrary form]
The above-mentioned HUD device is particularly suitable for projecting an image on the windshield of an automobile, but of course, the image may be projected on the side glass of the automobile or the like. When projecting an image on the side glass, a retardation film is placed on the side glass, and the Y-axis is horizontal to the ground and orthogonal to the traveling direction when the moving body moves forward, and the moving body moves horizontally and horizontally to the ground. The direction of travel of time may be set as the X-axis, and the other areas may be irradiated with projected light in the same manner as in the case of the windshield.

[Example when there are multiple viewers]
The HUD device according to the first embodiment of the present disclosure is any of the above, when there are a plurality of viewers and the image displayed in the central region of the windshield surface is visually recognized by the plurality of viewers from an angle. It can be a head-up display device that can suppress the generation of double images even from the viewpoint of the viewer.
The suppression of the occurrence of double images when the viewer is two people, a driver sitting in the position of the driver of the right-hand drive vehicle and a passenger seated in the passenger seat, will be described below.
The front of each of the driver and the passenger is the front area of the viewer in front of each viewer, and the area farther than the front area of the viewer is diagonally forward of the viewer along any direction in the X-axis direction. Let it be an area. Further, a region that is far from the viewer front region along the X-axis direction and the Z-axis direction is also defined as a viewer diagonally forward region.
The projected light is projected between the front area of each of the driver and the passenger, and is projected onto the central area, which is an area corresponding to the diagonally forward area of each of the driver and the passenger.

FIG. 9 is a diagram schematically showing an example of the relationship between the positions of the viewers and the projection unit and the orientation of the transmission axis of the polarizing unit when there are a plurality of viewers in the first HUD device.
In the first HUD device 1 shown in FIG. 9, the driver 35D and the passenger 35P, who are the viewers, visually recognize the image 621C projected on the central region.
Although one image 621C is displayed in FIG. 9, a plurality of images 621C may be displayed.

In FIG. 9, an image unit (not shown) is provided for each of the driver 35D and the passenger 35P, and each image unit projects projected light (front) so that the image 621C overlaps in the central region. Irradiate the glass surface).
In the vehicle, it is preferable that a plurality of image units are arranged on the dashboard of the vehicle according to a plurality of viewers.
Further, a polarizing unit 81D and a polarizing unit 81P are provided for each of the driver 35D and the passenger 35P. The polarizing unit 81D and the polarizing unit 81P are provided between the image unit and the projection unit corresponding to the driver 35D and the passenger 35P, respectively.
In the vehicle, the polarizing section 81D and the polarizing section 81P are arranged in the dashboard in the same manner as the video section, and are arranged adjacent to the light source so that the light from the light source quickly passes through the polarizing section 81D or the polarizing section 81P. It is preferable to be done.

The polarizing unit 81D has a transmission axis that transmits the projected light that vibrates in the direction parallel to the incident surface of the driver 35D, and the polarizing unit 81P transmits the projected light that vibrates in the direction parallel to the incident surface of the passenger 35P. It has a transmission axis.
The direction of the transmission axis of the polarizing section 81D and the direction of the transmission axis of the polarizing section 81P are different.
Specifically, the direction of the transmission axis of the polarizing portion 81D in FIG. 9 is the direction along the YY plane in the front region of the viewer, and in the direction rotated counterclockwise with this case as the reference line. be. The direction of the transmission axis of the polarizing portion 81P is the direction along the YY plane in the front region of the viewer, and is the direction rotated clockwise with this case as the reference line.
The orientation of the transmission axis of the polarizing section 81D and the orientation of the transmission axis of the polarizing section 81P are adjusted according to the relationship between the positions of the incident surface and the projection surface provided for each viewer. By doing so, when the image displayed in the central region of the windshield surface is visually recognized by a plurality of viewers (driver and passenger) from an angle, the double image can be seen from any of the viewers. It can be a head-up display device that can suppress the occurrence.

FIG. 10 is a diagram schematically showing an example of the relationship between the positions of the viewers and the projection unit and the orientation of the transmission axis of the polarizing unit when there are a plurality of viewers in the second HUD device.
In the second HUD device 2 shown in FIG. 10, the driver 35D and the passenger 35P, who are the viewers, visually recognize the image 421C projected on the central region.

An incident surface is provided for each of the driver 35D and the passenger 35P.
Further, a polarizing unit 82D and a polarizing unit 82P are provided for each of the driver 35D and the passenger 35P.
The polarizing unit 82D transmits through the polarizing unit 82D when the angle of the optical axis of the retardation film is θ _r and the angle of the incident surface for the driver 35D with respect to the X axis on the projection surface is θ _p . _{The vibration direction θ α} of the projected light incident on the projection surface is provided so as to satisfy θ _α = 2 _{θ r} −θ _p.
Further, the polarizing unit 82P transmits the polarizing unit 82P when the angle of the optical axis of the retardation film is θ _r and the angle of the incident surface for the passenger 35P with respect to the X axis on the projection surface is θ _p. _{Therefore, the vibration direction θ α} of the projected light incident on the projection surface is provided so as to satisfy θ _α = 2 _{θ r} −θ _p.
The direction of the transmission axis of the polarizing unit 82D is different from the direction of the transmission axis of the polarizing unit 82P.
Specifically, the direction of the transmission axis of the polarizing portion 82D in FIG. 10 is the direction along the XY plane in the front region of the viewer, and is the direction rotated clockwise with this case as the reference line. .. The direction of the transmission axis of the polarizing unit 82P is the direction along the XY plane in the front region of the viewer, and is the direction of rotation counterclockwise with this case as the reference line.
The direction of the transmission axis of the polarizing unit 82D and the direction of the transmission axis of the polarizing unit 82P are adjusted according to the relationship between the positions of the incident surface and the projection surface provided for each viewer. By doing so, when the image displayed in the central region of the windshield surface is visually recognized by a plurality of viewers (driver and passenger) from an angle, the double image can be seen from any of the viewers. It can be a head-up display device that can suppress the occurrence.

[Head-up display system (HUD system)]
The HUD system according to the first embodiment of the present disclosure is a system capable of switching the vibration direction of the light transmitted through the polarizing portion in one system.
Then, by changing the vibration direction of the light transmitted through the polarizing portion, the system can be used as both the first HUD device and the second HUD device.
Specifically, the following (A) and (B) can be switched.
(A) The vibration direction of the light incident on the second glass plate is set to be a direction parallel to the incident surface.
(B) the retardation film, when the angle between the vibration direction theta _alpha and the optical axis of the projection light incident on the projection plane and d [theta], thereby 2dθ rotational vibration direction of the projection light incident Assuming that, the vibration direction of the light transmitted through the second glass plate is the direction _{of 2θ r} − θ _{p on} the projection surface when _{the angle of the incident surface with respect to the X axis on the projection surface is θ p.} To be.
When the above (A) is performed, it becomes P-HUD and can be used as the first HUD device.
When the above (B) is performed, it becomes S-HUD and can be used as a second HUD device.

Further, the projection position on which the projected light is projected may be changed in the projection unit.
In the case of the first HUD device, the polarizing portion has a transmission axis that transmits light oscillating in a specific direction parallel to the incident surface.
Here, when the projection position is changed, the incident surface is changed.
If the position of the polarizing portion remains the same when the incident surface is changed, the vibration direction of the light transmitted through the polarizing portion deviates from the direction parallel to the incident surface. Therefore, the proportion of light that is not P-polarized light increases after passing through the polarized light portion, and a double image is likely to occur.
Therefore, when the projection position is changed, the polarizing portion is moved according to the projection position to change the vibration direction of the projected light transmitted through the polarizing portion, and the light vibrates in a direction parallel to the changed incident surface. Allow light to pass through.
As a result, even if the projection position is changed, the double image can be suppressed.

The same applies to the case of the second HUD device, and the polarizing unit and the transmission axis are moved according to the change in the projection position and the change in the incident surface.
Specifically, when the angle of the changed incident surface with respect to the X axis on the changed projection surface is θ _p _{, the direction of 2θ r} _{− θ p} on the changed projection surface (angle of the optical axis of the retardation film). Is made to transmit light such that _{is θ r).}
As a result, even if the projection position is changed, the double image can be suppressed.

(Example according to the first embodiment of the present disclosure)
An experiment was conducted to compare the generation of double images when the vibration direction of the light transmitted through the polarizing portion was changed in each of the front area of the viewer and the diagonally front area of the viewer.
First, the experimental results when the first HUD device is used are shown.
FIG. 11 is a layout diagram schematically showing the first HUD apparatus used in Examples and Comparative Examples.
FIG. 12 is a diagram schematically showing the experimental system in Example 1, and FIG. 13 is a diagram schematically showing the experimental system in Comparative Example 1.

A first HUD device as shown in FIG. 11 was prepared. The first HUD device 1 has a 150 mm × 150 mm square projection unit for the P-HUD system. The optical axis of the retardation film in the first HUD device 1 was set to 45 °.
As shown in FIG. 11, the image unit 31 is placed horizontally, and the vehicle laminated glass 10 is arranged with respect to the image unit 31 in a positional relationship of 57 ° forming a Brewster angle.
By placing a polarizing plate as a polarizing unit 81 on the image unit 31, the polarizing unit 81 is arranged between the image unit 31 and the laminated glass 10 for a vehicle.
The image unit 31 irradiates the projected light vertically upward, and the viewer 35 observes a virtual image on the extension of the optical path based on the reflected image on the first main surface 111.
The viewpoint of the viewer and the height of the laminated glass for the vehicle are the same.
A tablet is used as the image unit 31, and a green grid image is displayed from the tablet. A polarizing plate is placed on the tablet and placed directly under the laminated glass for vehicles.
Further, in order to simulate the traveling of the moving body at night, a black background plate 37 is arranged on the other side of the laminated glass 10 for the vehicle in the direction in which the viewer 35 visually recognizes the moving body.

As shown in FIGS. 12 and 13, the front of the viewer 35 was set as the point of position 0 in the X-axis direction as the observation point, and the -200 mm point and the -400 mm point were provided on the left side.
The left side in the X-axis direction is the "-" direction, and the right side is the "+" direction.
In the first embodiment, as shown in FIG. 12, the transmission axis of the polarizing portion 81 is set to 0 ° with the Y-axis direction as a reference line in the front area of the viewer (the point at the position 0 in the X-axis direction).
In FIGS. 12 and 13 and FIGS. 15 and 16 described later, the position of the polarizing portion is shown as the position on the XY plane, and the position of the laminated glass for the vehicle is shown as the position on the XY plane.
The transmission axis of the polarizing portion 81 was rotated counterclockwise at the -200 mm point and the -400 mm point, which are diagonally forward regions of the viewer. The rotation angles were + 10 ° and + 25 °, respectively. The rotation angle is + in the counterclockwise direction and-in the clockwise direction.
In the above experiment, the position of the viewer 35 was fixed, the position of the projection portion of a 150 mm × 150 mm square was shifted by -200 mm in the X-axis direction, and the image portion was further shifted by -200 mm in the X-axis direction. Was also performed by shifting by −200 mm in the X-axis direction so as to be arranged between the projection unit and the image unit.
In Comparative Example 1, as shown in FIG. 13, the transmission axis of the polarizing unit 81 was set to 0 ° with the Y-axis direction as the reference line at all observation points.

FIG. 14 is a photograph showing a virtual image visually recognized in Example 1 and Comparative Example 1.
Comparing the two at the same distance from the viewer, it was confirmed that in Example 1, the occurrence of double images was suppressed at the -200 mm point and the -400 mm point, which correspond to the diagonally forward region of the viewer.
On the other hand, in Comparative Example 1, double images extending in the horizontal and vertical directions were observed at these points.

Next, the experimental results when the second HUD device is used are shown.
The experimental system itself is similar to the first HUD apparatus shown in FIG. Instead of the polarizing unit 81, a polarizing plate as the polarizing unit 82 used in the second HUD device is used. In addition, the viewer 35 observes a virtual image on the extension of the optical path based on the reflected image on the fourth main surface 124.
FIG. 15 is a diagram schematically showing the experimental system in Example 2, and FIG. 16 is a diagram schematically showing the experimental system in Comparative Example 2.

As shown in FIGS. 15 and 16, the front of the viewer 35 was set as the point of position 0 in the X-axis direction as the observation point, and the -200 mm point and the -400 mm point were provided on the left side.
The left side in the X-axis direction is the "-" direction, and the right side is the "+" direction.
In the second embodiment, as shown in FIG. 15, the transmission axis of the polarizing unit 82 is set to 0 ° with the X-axis direction as the reference line in the front area of the viewer (the point at the position 0 in the X-axis direction).
The transmission axis of the polarizing portion 82 was rotated clockwise at the −200 mm point and the −400 mm point, which are the areas diagonally forward to the viewer. The rotation angles were -15 ° and -20 °, respectively. The rotation angle is + in the counterclockwise direction and-in the clockwise direction.
In the above experiment, the position of the viewer 35 was fixed, the position of the projection portion of a 150 mm × 150 mm square was shifted by -200 mm in the X-axis direction, and the image portion was further shifted by -200 mm in the X-axis direction. Was also performed by shifting by −200 mm in the X-axis direction so as to be arranged between the projection unit and the image unit.
In Comparative Example 2, as shown in FIG. 16, the transmission axis of the polarizing unit 82 was set to 0 ° with the X-axis direction as the reference line at all observation points.

FIG. 17 is a photograph showing a virtual image visually recognized in Example 2 and Comparative Example 2.
Comparing the two at the same distance from the viewer, it was confirmed that in Example 2, the occurrence of double images was suppressed at the -200 mm point and the -400 mm point, which correspond to the diagonally forward region of the viewer.
On the other hand, in Comparative Example 2, double images extending in the horizontal and vertical directions were observed at these points.

(Second Embodiment)
The head-up display device (HUD device), retardation film, laminated glass for vehicles, and head-up display system (HUD system) according to the second embodiment of the present disclosure will be described with reference to the drawings.

The HUD device according to the second embodiment of the present disclosure includes a HUD device including an image unit that irradiates a projected light whose vibration direction is the X direction, and a projected light whose vibration direction is parallel to the YZ plane. There is a HUD device provided with an image unit to be irradiated, and each is also referred to as a third HUD device and a fourth HUD device. In the description of the head-up display device according to the second embodiment of the present disclosure, when the third HUD device and the fourth HUD device are not distinguished, it is simply referred to as the HUD device according to the second embodiment of the present disclosure.
Further, the HUD system according to the second embodiment of the present disclosure can be used as both a third HUD device and a fourth HUD device by switching the type of projected light emitted in one system. It is a system that has been used.

The retardation film according to the second embodiment of the present disclosure is a retardation film that can be used for the laminated glass for vehicles, the HUD device, and the HUD system according to the second embodiment of the present disclosure. The vehicle laminated glass according to the second embodiment of the present disclosure is a vehicle laminated glass that can be used for the HUD device and the HUD system according to the second embodiment of the present disclosure.

First, the retardation film according to the second embodiment of the present disclosure will be described, and then the laminated glass for vehicles according to the second embodiment of the present disclosure will be described.
Subsequently, the HUD device according to the second embodiment of the present disclosure will be described, and finally, the HUD system according to the second embodiment of the present disclosure will be described.

[Phase difference film]
The retardation film according to the second embodiment of the present disclosure is an integral retardation film having a vertical axis in the vertical direction and a horizontal axis in the horizontal direction, and is positioned at a plurality of points along the vertical axis. The angle formed by the optical axis and the horizontal axis of the retardation film is constant, and the angle formed by the optical axis and the horizontal axis of the retardation film changes with a constant tendency along the horizontal axis direction.
In the second embodiment of the present disclosure, the optical axis of the retardation film means the axis in the direction in which the refractive index of the retardation film is the largest.
The retardation film in the second embodiment of the present disclosure is a 1/2 wavelength film (half wavelength film).

FIG. 18 is a drawing schematically showing an example of a retardation film according to the second embodiment of the present disclosure.
FIG. 18 schematically shows the optical axis of the retardation film at each point of the retardation film 201. In addition, the directions of the "horizontal axis" and the "vertical axis" are shown.
In P ₁ point in FIG. 18, the angle formed with the optical axis and the horizontal axis of the retardation film is 45 °.
The angle formed by the optical axis and the horizontal axis of the retardation film is defined as the smaller angle of the angles formed at the intersections of the two straight lines. When the optical axis and the horizontal axis of the retardation film are parallel, the angle formed by the optical axis and the horizontal axis of the retardation film is 0 °.
At a plurality of points along the vertical axis, P ₁ , P ₂ , and P ₃ , the angle formed by the optical axis and the horizontal axis of the retardation film is constant and is 45 °.

In the retardation film according to the second embodiment of the present disclosure, the angle formed by the optical axis and the horizontal axis of the retardation film changes with a constant tendency along the horizontal axis direction.
FIG. 18 shows a retardation film in a form in which the angle formed by the optical axis and the horizontal axis of the retardation film continuously changes along the horizontal axis direction.

The retardation film 201 illustrated in FIG. 18, located on the right N ₁ point along the horizontal axis from P ₁ point is a point located on the left side, from O ₁ point and P ₁ point along the horizontal axis in which _{Q 1} point point, shows the _{R 1} point.
In each point from left to right in FIG. 18, the angle formed with the optical axis and the horizontal axis of the retardation film, 35 ° in N ₁ point, 40 ° in the O ₁ point, 45 ° at P ₁ point, Q ₁ 50 ° is the point, in R ₁ point has a 55 °, along the horizontal axis, it can be seen that the angle between the optical axis and the horizontal axis of the retardation film is changed at a constant tendency.
Further, since the angle between the optical axis and the horizontal axis of the retardation film varies continuously, between, for example, O ₁ point and P ₁ point, position at each point from left to right in FIG. 18 The angle formed by the optical axis and the horizontal axis of the retardation film continuously changes from 40 ° to 45 °.

FIG. 19 is a drawing schematically showing an example of another retardation film according to the second embodiment of the present disclosure.
FIG. 19 shows a retardation film in a form in which the angle formed by the optical axis and the horizontal axis of the retardation film changes discontinuously along the horizontal axis direction.
The retardation film 202 illustrated in FIG. 19, in the vicinity of the horizontal axis center angle formed with the optical axis and the horizontal axis of the retardation film indicates the p ₁ region is 45 °. is indicated by double arrow a width of p ₁ region on the phase difference film 202.
In the p ₁ region, the optical axis and the horizontal axis and the angle formed of the retardation film are all the same 45 °.

The retardation film 202 illustrated in FIG. 19, located on the right side along n ₁ region is a region located on the left side from p ₁ region along the horizontal axis, from o ₁ region and the p ₁ region in the horizontal axis direction The q ₁ region and the r ₁ region, which are regions, are shown.
The boundaries of each region are shown by dotted lines in FIG.
The angles formed by the optical axis and the horizontal axis of the retardation film in each region are all the same.

In each region from left to right in FIG. 19, the angles formed by the optical axis and the horizontal axis of the retardation film are 35 ° in the _{n 1} region, 40 ° in the _{o 1} region, 45 ° in the _{p 1} _{region, and q 1} 50 ° in the region, the r ₁ region has a 55 °, along the horizontal axis, it can be seen that the angle between the optical axis and the horizontal axis of the retardation film is changed at a constant tendency.
Further, since the angle formed by the optical axis and the horizontal axis of the retardation film is the same in each region, it can be seen that the angle formed by the optical axis and the horizontal axis of the retardation film changes discontinuously.

In the explanation so far, the retardation film having a point or region where the angle formed by the optical axis and the horizontal axis of the retardation film is 45 ° has been described, but the angle formed by the optical axis and the horizontal axis of the retardation film has been described. The specific value of is not limited to the range of the above-mentioned example. A retardation film according to the second embodiment of the present disclosure is a retardation film in which the angle formed by the optical axis and the horizontal axis of the retardation film changes with a constant tendency along the horizontal axis direction. Further, when the angle formed by the optical axis and the horizontal axis of the retardation film changes discontinuously, the width at which the angle changes between adjacent regions is not limited to 5 °. Further, the width at which the angle changes between adjacent regions does not have to be constant.

As the retardation film, a retardation element obtained by uniaxially or biaxially stretching a plastic film such as polycarbonate, polyarylate, polyether sulfone, cycloolefin polymer, triacetyl cellulose, polyethylene terephthalate (PET), or polyethylene naphthalate (PEN). Alternatively, a retardation element in which the liquid crystal polymer is oriented in a specific direction and the orientation state is fixed can be used.
As the former phase difference element obtained by stretching a plastic film uniaxially or biaxially, for example, a polymer resin is dissolved in a solvent and then applied on a smooth surface such as a stainless steel belt or polyethylene terephthalate (PET) to evaporate the solvent. The film is formed by a solvent casting method in which the film is wound after being wound, or a melt extrusion method in which a polymer resin is placed in an extruder to be heated and melted, extruded from a slit (T die), cooled, and then the film is wound. Can be used. A stretching machine is generally used for stretching, and a retardation film stretched vertically, horizontally, diagonally, or the like can be obtained.
As the latter retardation element, for example, a liquid crystal polymer is coated on a transparent substrate such as a transparent plastic film such as polyethylene terephthalate (PET) or triacetyl cellulose (TAC) which has been oriented, and heat-treated and cooled to align the liquid crystal. A fixed one can be used.
Examples of the above-mentioned liquid crystal polymer are not particularly limited as long as they are compounds exhibiting liquid crystal properties such as nematic liquid crystal, twisted nematic liquid crystal, discotic liquid crystal, and cholesteric liquid crystal when oriented in a specific direction. For example, those that are twisted and nematically oriented in the liquid crystal state and are in the glass state below the liquid crystal transition point can be used, and can be used as a main chain type liquid crystal polymer such as optically active polyester, polyamide, polycarbonate, polyesterimide, or optically active poly. Examples thereof include side-chain liquid crystal polymers such as acrylate, polymethacrylate, polycarbonate, and polysiloxane. Further, a polymer composition obtained by adding another small molecule or high molecular weight optically active compound to these non-optically active main chain type or side chain type polymers can be exemplified.

Examples of the alignment treatment method include a method of rubbing the surface of a plastic film to be a transparent substrate, or a method of forming an organic thin film (alignment film) such as polyimide on a glass plate or a plastic film and rubbing the alignment film. Alternatively, a method of photoalignment treatment or the like can be mentioned. As the rubbing treatment, a method of rubbing the surface of a plastic film or an alignment film with a rubbing cloth such as nylon or rayon can be applied.
As a method for applying the liquid crystal polymer, generally known methods such as spin coating, die coating, spray coating, calendar coating, and gravure coating can be used.
Further, in a retardation film in which the angle formed by the optical axis and the horizontal axis of the retardation film changes discontinuously, a plurality of retardation films are laminated by tilting the retardation films so that the optical axes of the retardation films are different for each region. Alternatively, it may be produced by laminating.

The retardation film 201 shown in FIG. 18 and the retardation film 202 shown in FIG. 19 are the laminated glass for vehicles according to the second embodiment of the present disclosure, the HUD device according to the second embodiment of the present disclosure, and the present disclosure. It can be used to obtain the HUD system according to the second embodiment.
That is, by using the retardation film according to the second embodiment of the present disclosure, it is possible to provide a HUD device having a wide display area in the lateral direction of the windshield surface.

[Laminated glass for vehicles]
The laminated glass for a vehicle according to the second embodiment of the present disclosure includes a first glass plate, a second glass plate, and a retardation film arranged between the first glass plate and the second glass plate. It is a laminated glass for a vehicle, and the retardation film is a retardation film according to the second embodiment of the present disclosure.

FIG. 20 is an exploded perspective view schematically showing an example of a laminated glass for a vehicle according to a second embodiment of the present disclosure.
The first glass plate includes a first main surface exposed to the outdoor side and a second main surface opposite to the first main surface.
Further, the second glass plate includes a fourth main surface exposed to the indoor side and a third main surface opposite to the fourth main surface.
FIG. 20 shows a laminated glass 210 for a vehicle.
FIG. 20 shows a view in which the second glass plate 12 is arranged on the front side of the drawing, and the surface visible on the front side is the fourth main surface 124. The surface opposite to the fourth main surface 124 is the third main surface 123.
The first glass plate 11 is arranged on the back side of the drawing, and the surface visible on the front side is the second main surface 112. The surface opposite to the second main surface 112 is the first main surface 111.
The retardation film 201 described with reference to FIG. 18 is arranged between the first glass plate 11 and the second glass plate 12.
Since the fourth main surface 124 is a surface exposed to the indoor side, it is a surface that the viewer can directly see when the laminated glass for the vehicle is arranged on the vehicle. That is, FIG. 20 shows the positional relationship in which the viewer directly sees from the inside of the vehicle.

The vehicle laminated glass 210 is a vehicle laminated glass for a right-hand drive vehicle, and the viewer who visually recognizes the HUD image is the driver. The position of the retardation film 201 is determined so that the point where the angle formed by the optical axis and the horizontal axis of the retardation film is 45 ° is in front of the viewer who is the driver in the right-hand drive vehicle.
Further, the angle formed by the optical axis and the horizontal axis on the left side of the viewer is smaller than 45 °, and the angle formed by the optical axis and the horizontal axis on the right side of the viewer is larger than 45 °.

FIG. 20 shows a case where the optical axis is rising to the right in front of the viewer and the angle formed by the optical axis and the horizontal axis is 45 °, but the optical axis is on the left in front of the viewer. The angle between the optical axis and the horizontal axis may be 45 °. When the optical axis is rising to the left in front of the viewer, the angle between the optical axis and the horizontal axis is larger than 45 ° on the left side of the viewer, and the angle between the optical axis and the horizontal axis is on the right side of the viewer. It is smaller than 45 °.
Regarding the angle formed by the optical axis and the horizontal axis when the optical axis is rising to the left, the angle is obtuse if the same angle is taken as when the optical axis is rising to the right. It shall refer to the value of the acute angle that is the complementary angle of.

The retardation film is arranged between the first glass plate and the second glass plate.
The retardation film may be arranged inside the interlayer film, may be arranged at a position in contact with the first glass plate, or may be arranged at a position in contact with the second glass plate.
By arranging the first glass plate and the second glass plate in the horizontal direction and the lateral axis direction of the retardation film in the same direction, a laminated glass for a vehicle as a windshield can be obtained.

As the glass material constituting the laminated glass for vehicles, a flat glass plate processed into a curved shape can be preferably used. As the material of the glass plate, in addition to soda lime silicate glass as specified in ISO16293-1, a glass having a known glass composition such as aluminosilicate glass, borosilicate glass, and non-alkali glass can be used. can. The thickness of each of the first glass plate and the second glass plate may be, for example, 0.4 mm to 3 mm. The distance between the first glass plate and the second glass plate may be 0.05 mm to 1 mm.

FIG. 20 shows the laminated glass for vehicles on which the retardation film 201 described in FIG. 18 is arranged, but the laminated glass for vehicles using the retardation film 202 described in FIG. 19 as the retardation film is also present. It is a laminated glass for a vehicle according to the second embodiment of the disclosure.

The laminated glass for vehicles according to the second embodiment of the present disclosure can be used to obtain the HUD device according to the second embodiment of the present disclosure and the HUD system according to the second embodiment of the present disclosure.
That is, by using the laminated glass for vehicles according to the second embodiment of the present disclosure, it is possible to provide a HUD device having a wide display area in the lateral direction of the windshield surface.

Further, similarly to the windshield, the area where the HUD image is displayed may be enlarged by using the above-mentioned laminated glass for vehicles for the side glass. The projection portion on which the projected light at this time is projected is preferably in front of the side of the viewer.

[Head-up display device (HUD device)]
There are two types of HUD devices according to the second embodiment of the present disclosure, a third HUD device and a fourth HUD device. First, the definitions of the X-axis, Y-axis, and Z-axis, the definition of the moving body, and the example of the moving body, which are common to both HUD devices, are the same as those of the HUD device and the moving body according to the first embodiment of the present disclosure. Is.

As the laminated glass for vehicles used in the HUD device, the laminated glass for vehicles according to the second embodiment of the present disclosure can be used.

[Third HUD device]
The third HUD device is a device for observing a reflected image formed on the fourth main surface of the second glass plate as a virtual image, and is an S-HUD type HUD device.
FIG. 21 is a schematic view showing an outline of a third HUD device according to the first aspect of the second embodiment of the present disclosure and an optical path in the device.
In this schematic view, a visual figure is set as a driver, and a schematic view of a cross section in a visible person front area, which is the front of the visual person, is shown. The direction perpendicular to the paper surface is the X-axis.
In FIG. 21, the optical path of the projected light is shown by a solid line.
In the third HUD device 3, the projection unit is a laminated glass 210 for a vehicle, and the laminated glass 210 for a vehicle is on the first glass plate 11 arranged on the outdoor side of the vehicle, which is a moving body, and on the indoor side of the vehicle. It includes a second glass plate 12 to be arranged.
The first glass plate 11 includes a first main surface 111 exposed to the outdoor side and a second main surface 112 on the opposite side of the first main surface 111.
Further, the second glass plate 12 includes a fourth main surface 124 exposed to the indoor side and a third main surface 123 on the opposite side of the fourth main surface 124.
A retardation film 201 is arranged between the first glass plate 11 and the second glass plate 12.

The projected light 240 is irradiated from the image unit 31 to the fourth main surface 124, and a reflected image is formed on the fourth main surface 124. The viewer 35 observes the virtual image 412 on the extension of the optical path 241 based on the reflected image formed on the fourth main surface 124.

In the third HUD device 3, the image unit 31 irradiates the projected light 240 whose vibration direction is the X-axis direction.
Here, the plane including the light emitting point 32 of the image unit 31, the reflection point 33 on which the projected light 240 is reflected on the fourth main surface 124, and the viewpoint 34 of the viewer 35 is the incident surface.
In FIG. 21, the paper surface corresponds to substantially the same surface as the incident surface.
Light whose vibration direction is perpendicular to the incident surface is S-polarized light. When the incident surface is perpendicular to the X-axis, when the projected light whose vibration direction is the X-axis direction is incident on the incident surface, the projected light becomes S-polarized.

When the projected light is S-polarized light, the projected light transmitted through the fourth main surface 124 and traveling in the projection portion is converted to P-polarized light by passing through the retardation film 201, and is converted to P-polarized light on the first main surface 111. The projected light is emitted to the outdoor side as P-polarized light without any reflection.
If the reflection on the first main surface 111 can be suppressed in this way, the generation of the double image is suppressed.

When the viewer sees the reflected image formed in the front area of the viewer, the retardation film arranged in the front area of the viewer has the optical axis of the retardation film on the X-axis in a plane parallel to the fourth main surface. On the other hand, it is 45 ° ± 5 °.
If the optical axis of the retardation film 201 through which S-polarized light having a vibration direction along the X-axis is transmitted is 45 ° ± 5 ° with respect to the X-axis, the ratio of S-polarized light being converted to P-polarized light is large. .. In the front area of the viewer, the incident surface is perpendicular to the X-axis and the projected light is S-polarized. Therefore, the optical axis of the corresponding retardation film is set to 45 ° ± 5 ° with respect to the X-axis. The generation of heavy images can be suppressed.

Next, a case will be described in which the viewer sees a reflected image formed in a region diagonally forward to the viewer, which is a region far from the front region of the viewer, along any direction in the X-axis direction.
When the viewer looks at the area diagonally forward of the viewer, the incident surface is different from when the viewer looks at the area in front of the viewer. Since the vibration direction of the projected light remains the X-axis direction, the vibration direction (X-axis) of the projected light with respect to the incident surface deviates from the vertical direction, and the projected light becomes a mixed light of S-polarized light and P-polarized light, and the viewer The farther from the front region, the higher the proportion of the P polarization component.
If the optical axis of the retardation film is left at 45 ° ± 5 ° with respect to the X-axis with respect to such mixed light, the proportion of P-polarized light in the projected light after passing through the retardation film is small. As a result, the proportion of S-polarized light becomes high.
Therefore, when the viewer sees the reflected image formed in the diagonally forward region of the viewer, the optical axis of the retardation film is 45 ° ± with respect to the X axis for the retardation film arranged in the obliquely front region of the viewer. By shifting from 5 °, the proportion of the component that becomes P-polarized light after the mixed light of S-polarized light and P-polarized light passes through the retardation film is increased, and the generation of double image is suppressed.

In both the front area of the viewer and the diagonally front area of the viewer, the projected light is incident on the retardation film so that the vibration direction of the projected light is converted to a direction parallel to the incident surface. Light whose vibration direction is parallel to the incident surface is P-polarized light.
If the projected light after passing through the retardation film is P-polarized, the projected light is emitted to the outdoor side as P-polarized light without being reflected on the first main surface. Therefore, the generation of the double image is suppressed in both the front area of the viewer and the diagonally front area of the viewer, and the generation of the double image is suppressed even when the display area of the HUD is enlarged in the lateral direction of the windshield surface. It becomes a possible HUD device.

FIG. 22 is a diagram schematically showing the positions of the viewer front region and the viewer diagonally forward region when the driver of the right-hand drive vehicle is a viewer.
FIG. 22 shows only the laminated glass 210 for vehicles constituting the HUD device, and schematically shows the direction of the optical axis of the retardation film constituting the laminated glass 210 for vehicles.
In a right-hand drive vehicle, the right side of the drawing of the laminated glass 210 for a vehicle corresponds to the front of the viewer 35, so the viewer front area 250 is provided in this portion. In the viewer front region 250, the optical axis of the retardation film is 45 ° ± 5 ° with respect to the X axis.
The region distant from the viewer front region 250 along the right direction in the X-axis direction is the right peripheral region 251. On the other hand, the region distant from the viewer front region 250 along the left direction in the X-axis direction is the left peripheral region 252.
In the right peripheral region 251, the optical axis of the retardation film is shifted in a direction larger than 50 ° with respect to the X axis. On the other hand, in the left peripheral region 252, the optical axis of the retardation film is shifted in a direction smaller than 40 ° with respect to the X axis.
That is, in the right peripheral region and the left peripheral region, the directions in which the optical axis of the retardation film deviates from the X axis by 45 ° ± 5 ° are opposite.
The same applies when the occupant in the passenger seat of the left-hand drive vehicle is a visible person.

FIG. 23 is a diagram schematically showing the positions of the viewer front region and the viewer diagonally forward region in the left-hand drive vehicle.
In a left-hand drive vehicle, the left side of the drawing of the laminated glass 210 for a vehicle corresponds to the front of the viewer 35, so the viewer front area 250 is provided in this portion. In the viewer front region 250, the optical axis of the retardation film is 45 ° ± 5 ° with respect to the X axis. Similar to the embodiment shown in FIG. 22, the region farther from the viewer front region 250 along the right direction in the X-axis direction is the right peripheral region 251, and the viewer front region along the left direction in the X-axis direction. The region farther from 250 is the left peripheral region 252.
In the right peripheral region 251, the optical axis of the retardation film is shifted in a direction larger than 50 ° with respect to the X axis. On the other hand, in the left peripheral region 252, the optical axis of the retardation film is shifted in a direction smaller than 40 ° with respect to the X axis.
That is, in the right peripheral region and the left peripheral region, the directions in which the optical axis of the retardation film deviates from the X axis by 45 ° ± 5 ° are opposite.
The same applies when the occupant in the passenger seat of a right-hand drive vehicle is a visible person.

FIG. 24 is a diagram schematically showing another aspect of the positions of the viewer front region and the viewer oblique front region when the driver of the right-hand drive vehicle is a viewer.
The direction of the optical axis of the retardation film is different from that shown in FIG. In the aspect shown in FIG. 22, the optical axis rises to the right in front of the viewer and the angle formed by the optical axis and the horizontal axis is 45 °, but in the aspect shown in FIG. 24, the optical axis is in front of the viewer. Is rising to the left, and the angle between the optical axis and the horizontal axis is 45 °.
In the right peripheral region 251, the optical axis of the retardation film is shifted in a direction smaller than 40 ° with respect to the X axis. On the other hand, in the left peripheral region 252, the optical axis of the retardation film is shifted in a direction larger than 50 ° with respect to the X axis.
That is, in the right peripheral region and the left peripheral region, the directions in which the optical axis of the retardation film deviates from the X axis by 45 ° ± 5 ° are opposite.
The same applies when the occupant in the passenger seat of the left-hand drive vehicle is a visible person.

FIG. 25 is a diagram schematically showing another aspect of the positions of the viewer front region and the viewer oblique front region when the driver of the left-hand drive vehicle is a viewer.
The direction of the optical axis of the retardation film is different from that shown in FIG. 23. In the aspect shown in FIG. 23, the optical axis rises to the right in front of the viewer and the angle formed by the optical axis and the horizontal axis is 45 °, but in the aspect shown in FIG. 25, the optical axis is in front of the viewer. Is rising to the left, and the angle between the optical axis and the horizontal axis is 45 °.
In the right peripheral region 251, the optical axis of the retardation film is shifted in a direction smaller than 40 ° with respect to the X axis. On the other hand, in the left peripheral region 252, the optical axis of the retardation film is shifted in a direction larger than 50 ° with respect to the X axis.
That is, in the right peripheral region and the left peripheral region, the directions in which the optical axis of the retardation film deviates from the X axis by 45 ° ± 5 ° are opposite.
The same applies when the occupant in the passenger seat of a right-hand drive vehicle is a visible person.

FIG. 26 is a diagram schematically showing the positions of the viewer front region and the viewer oblique front region when there are two viewers, the driver and the passenger seat occupant.
In this aspect, the driver and the passenger seat occupant are made to visually recognize different images.
The angle formed by the optical axis and the X-axis of the retardation film is optimized for each viewer in the front area of the viewer and the diagonally front region of the viewer.
When there are two viewers, a driver and a passenger seat occupant, a viewer front area 250 is provided for the viewer 35 as a driver shown on the right side of FIG. 26, and is provided along the right direction in the X-axis direction. A right peripheral area 251 is provided in an area far from the viewer front area 250.
Further, a viewer front area 250'is provided for the viewer 35'as a passenger seat occupant shown on the left side of FIG. 26, and is far from the viewer front area 250' along the left direction in the X-axis direction. A left peripheral area 252'is provided in the area.
Note that FIG. 26 assumes a right-hand drive vehicle in which the driver's seat is on the right side and the passenger seat is on the left side, but the same applies to a left-hand drive vehicle in which the driver's seat is on the left side and the passenger seat is on the right side.

In the aspect shown in FIG. 26, the left peripheral area with respect to the visual view 35 as a driver and the right peripheral area with respect to the visual figure 35'as a passenger seat occupant are not provided, but the projection unit with respect to the visual view 35 as a driver is not provided. , These areas may be provided depending on the arrangement of the projection unit with respect to the viewer 35'who is a passenger in the passenger seat.
Further, a plurality of retardation films as shown in FIG. 20 may be used in combination so that the projected light can be visually recognized by each viewer.

FIG. 27 is a diagram schematically showing another aspect of the positions of the viewer front region and the viewer oblique front region when there are two viewers, the driver and the passenger seat occupant.
The direction of the optical axis of the retardation film is different from that shown in FIG. In the aspect shown in FIG. 26, the optical axis rises to the right in front of the viewer and the angle formed by the optical axis and the horizontal axis is 45 °, but in the aspect shown in FIG. 27, the optical axis is in front of the viewer. Is rising to the left, and the angle between the optical axis and the horizontal axis is 45 °.
In the right peripheral region 251 with respect to the viewer 35 as a driver, the optical axis of the retardation film is shifted in a direction smaller than 40 ° with respect to the X axis. On the other hand, in the left peripheral region 252'with respect to the viewer 35'as a passenger seat occupant, the optical axis of the retardation film is deviated in a direction larger than 50 ° with respect to the X axis.

The viewer oblique front region may be extended to the region diagonally in front of the viewer in the side glass arranged next to the viewer, or the projection portion may be extended to the side glass.
FIG. 28 is a diagram schematically showing a mode in which the projection portion is extended to the side glass.
FIG. 28 shows a side glass 270 arranged on the right side of the vehicle laminated glass 210. The viewer can visually recognize the projected light projected on the side glass 270 on the right side.
The region on which the projected light is projected on the side glass 270 is defined as the right extended region 271.
Even in the right-side expansion region 271, the angle of the optical axis of the retardation film changes in the right peripheral region of the viewer front region.
The generation of double images can be suppressed by the same idea even in the extended area in which the diagonally forward area of the viewer is extended to the side glass.

[Fourth HUD device]
The fourth HUD device is a device for observing a reflected image formed on the first main surface of the first glass plate as a virtual image, and is a P-HUD type HUD device.
FIG. 29 is a schematic diagram showing an outline of a fourth HUD device according to a second aspect of the second embodiment of the present disclosure and an optical path in the device.
In this schematic view, a visual figure is set as a driver, and a schematic view of a cross section in a visible person front area, which is the front of the visual person, is shown. Further, the paper surface is a surface parallel to the YZ plane.
In FIG. 29, the optical path of the projected light is shown by a solid line.
In the fourth HUD device 4, the projection unit is a laminated glass 210 for a vehicle, and the laminated glass 210 for a vehicle is on the first glass plate 11 arranged on the outdoor side of the vehicle, which is a moving body, and on the indoor side of the vehicle. It includes a second glass plate 12 to be arranged.
The first glass plate 11 includes a first main surface 111 exposed to the outdoor side and a second main surface 112 on the opposite side of the first main surface 111.
Further, the second glass plate 12 includes a fourth main surface 124 exposed to the indoor side and a third main surface 123 on the opposite side of the fourth main surface 124.
A retardation film 201 is arranged between the first glass plate 11 and the second glass plate 12.

In the fourth HUD device 4, the image unit 31 irradiates the projected light 260 whose vibration direction is parallel to the YZ plane.
Here, the plane including the light emitting point 32 of the image unit 31, the reflection point 33 on which the projected light 260 is reflected by the first main surface 111, and the viewpoint 34 of the viewer 35 is the incident surface.
In FIG. 29, the paper surface corresponds to substantially the same surface as the incident surface.
Light whose vibration direction is parallel to the incident surface is P-polarized light. When the incident surface is parallel to the YZ plane, when the projected light whose vibration direction is parallel to the YZ plane is incident on the incident surface, the projected light becomes P-polarized light.

When the projected light 260 is P-polarized, it can also be used in sunglasses mode, in which a virtual image is observed through polarized sunglasses.
The projected light 260 is emitted from the image unit 31 to the fourth main surface 124, and the projected light traveling in the projection unit is converted into S-polarized light by the retardation film 201 to form a reflected image on the first main surface 111. On the other hand, a part of the S-polarized light that was not reflected passes through the first main surface 111 and is emitted to the outdoor side as the S-polarized light.
The reflected image formed on the first main surface 111 passes through the retardation film 201 again and is converted into P-polarized light. The viewer 35 visually recognizes the virtual image 612 on the extension of the optical path 261 based on the reflected image on the first main surface 111.
Since the virtual image 612 is composed of P-polarized light, the viewer 35 can visually recognize the virtual image even through the polarized sunglasses 36.

A reflected image is not formed on the fourth main surface 124, or a reflected image is formed a little. When the intensity of the reflected image formed on the fourth main surface 124 is relatively stronger than that on the first main surface 111, the reflected image formed on the fourth main surface 124 is regarded as a double image. Observed.

When the viewer sees the reflected image formed in the front area of the viewer, the retardation film arranged in the front area of the viewer has the optical axis of the retardation film on the X-axis in a plane parallel to the fourth main surface. On the other hand, it is 45 ° ± 5 °.
In the front region of the viewer, the projected light is almost P-polarized. If the optical axis of the retardation film 201 through which P-polarized light is transmitted in the front region of the viewer is 45 ° ± 5 ° with respect to the X-axis, the ratio of P-polarized light converted to S-polarized light is large.
If the efficiency of converting the projected light (P-polarized light) incident on the retardation film into S-polarized light is high, the virtual image display based on the reflected image formed on the first main surface of the first glass plate becomes stronger. Therefore, the influence of the reflected image formed on the fourth main surface is relatively weakened, and the generation of the double image is suppressed.

Next, a case will be described in which the viewer sees a reflected image formed in a region diagonally forward to the viewer, which is a region far from the front region of the viewer, along any direction in the X-axis direction.
When the viewer looks at the area diagonally forward of the viewer, the incident surface is different from when the viewer looks at the area in front of the viewer. Since the vibration direction of the projected light remains parallel to the YZ plane, the vibration direction of the projected light with respect to the incident surface (direction parallel to the YZ plane) deviates from the parallel direction, and the projected light is S-polarized and P-polarized. The ratio of the S polarization component increases as the distance from the front region of the viewer increases.
If the optical axis of the retardation film is left at 45 ° ± 5 ° with respect to the X-axis with respect to such mixed light, the proportion of S-polarized light in the projected light after passing through the retardation film is small. As a result, the proportion of P-polarized light becomes high.
Therefore, when the viewer sees the reflected image formed in the diagonally forward region of the viewer, the optical axis of the retardation film is 45 ° ± with respect to the X axis for the retardation film arranged in the obliquely front region of the viewer. By shifting from 5 °, the proportion of the component that becomes S-polarized light after the mixed light of S-polarized light and P-polarized light passes through the retardation film is increased, and it is based on the reflection image formed on the first main surface of the first glass plate. Strengthen the virtual image display.
By strengthening the virtual image display based on the reflected image formed on the first main surface, the influence of the projected light reflected on the fourth main surface is relatively weakened, and the generation of the double image is suppressed.

In both the front area of the viewer and the diagonally front area of the viewer, the projected light is incident on the retardation film so that the vibration direction of the projected light is changed to the direction perpendicular to the incident surface. Light whose vibration direction is perpendicular to the incident surface is S-polarized light.
When the projected light after passing through the retardation film is S-polarized light, the reflection of the first main surface becomes strong, so that the virtual image display based on the reflected image formed on the first main surface of one glass plate becomes strong.
Therefore, the generation of the double image is suppressed in both the front area of the viewer and the diagonally front area of the viewer, and the generation of the double image is suppressed even when the display area of the HUD is enlarged in the lateral direction of the windshield surface. It becomes a possible HUD device.

In the fourth HUD device as well, the positions of the viewer front region and the viewer oblique front region can be determined in the same manner as in the third HUD device. Examples of the positions of the viewer front region and the viewer diagonally forward region in each of the right-hand drive vehicle and the left-hand drive vehicle can be as described with reference to FIGS. 22 and 23.
Further, an example in which the direction of the optical axis of the retardation film rises to the left can be as described with reference to FIGS. 24 and 25.
Further, an example in which there are two viewers can be as described with reference to FIGS. 26 and 27.
Further, an example in which the projection unit is extended to the side glass can be as described with reference to FIG. 28.

In both the third HUD device and the fourth HUD device described so far, the inclination of the retardation film in the direction of the optical axis in the diagonally forward region of the viewer is continuously changed along the X-axis direction. (That is, an example using the retardation film shown in FIG. 18) has been illustrated and described, but the change in the inclination of the retardation film in the direction of the optical axis in the diagonally forward region of the viewer is along the X-axis direction. (That is, an example using the retardation film shown in FIG. 19) may be used.

[Head-up display system (HUD system)]
The HUD system according to the second embodiment of the present disclosure is a system that can be used as both a third HUD device and a fourth HUD device by switching the type of projected light emitted in one system. Is.
In the HUD system, the image unit can switch between the first projected light whose vibration direction is the X-axis direction and the second projected light whose vibration direction is parallel to the YZ plane.
When irradiating the first projected light, it becomes S-HUD and can be used as a third HUD device. When irradiating the second projected light, it becomes P-HUD and can be used as a fourth HUD device.
It is used as a fourth HUD device when a viewer visually recognizes a virtual image through a polarizing plate such as polarized sunglasses.
The configuration other than the image unit in the HUD system can be the same as that of the third HUD device and the fourth HUD device.
The switching between the first projected light and the second projected light in the image unit will be described below.

The image unit may be a device capable of projecting the first projected light whose vibration direction is the X-axis direction, and projects the second projected light whose vibration direction is parallel to the YZ plane. It may be a device capable of
Further, the device may have two types of projection mechanisms and can switch the type of projected light.
Further, it is a device capable of converting the projected light into the first projected light or the second projected light by first irradiating the light of a certain polarization and arranging the polarization control unit in the optical path of the light. You may.
Types of projected light before conversion include those that randomly contain all kinds of polarized light (unpolarized light), circularly polarized light and elliptically polarized light, mixed light of P-polarized light and S-polarized light, P-polarized light, and linearly polarized light that is not S-polarized light. Can be mentioned.
As the image unit, a projector capable of irradiating the projected light is preferably used. Examples of such a projector include a DMD projection system projector, a laser scanning MEMS projection system projector, a reflective liquid crystal projector, and the like.

For example, when the image unit first has a mechanism for irradiating the first projected light whose vibration direction is the X-axis direction, a half-wave plate (vibration direction of the first projected light) is used as a polarization control unit in the optical path of the projected light. By providing a retardation film) in which the optical axis of the retardation film is 45 °, the first projected light can be converted into the second projected light.
When the first projected light is used as the projected light as it is, it may not pass through the polarization control unit, and when it is used as the second projected light, it may pass through the polarization control unit.
By controlling the passage / non-passage of the polarization control unit, it is possible to switch between the first projected light and the second projected light.

Even when the image unit first has a mechanism for irradiating the second projected light whose vibration direction is parallel to the YZ plane, the same configuration is used to convert the second projected light into the first projected light. Therefore, it is possible to switch between the second projected light and the first projected light by controlling the passage / non-passage of the polarization control unit.

In the fourth HUD device, the reflected image formed on the first main surface of the first glass plate is observed as a virtual image, but if the intensity of the projected light is the same as that of the third HUD device, the third HUD device The virtual image display is weaker than the reflected image formed on the fourth main surface of the second glass plate.
Therefore, it is preferable that the irradiation intensity when projecting the second projected light is higher than the irradiation intensity when projecting the first projected light. This can be done by switching the irradiation intensity of the projected light emitted from the image unit between the case of the first projected light and the case of the second projected light. Further, when the first projected light is projected, the irradiation intensity may be lowered by transmitting the ND filter or the like.

(Example according to the second embodiment of the present disclosure)
An experiment was conducted to compare the appearance of double images when the angle formed by the optical axis and the X-axis of the retardation film changes in each of the front area of the viewer and the diagonally front area of the viewer.
First, the experimental results for the case where the diagonally forward region of the viewer is on the right side of the viewer are shown.
FIG. 30 is a layout diagram schematically showing the third HUD device used in Examples and Comparative Examples.
FIG. 31 is a diagram schematically showing the experimental system in Example 3, and FIG. 32 is a diagram schematically showing the experimental system in Comparative Example 3.

A third HUD device as shown in FIG. 30 was prepared. The third HUD device 3 has a 200 mm × 200 mm square projection unit for the S-HUD system.
As shown in FIG. 30, the image unit 31 is placed horizontally, and the vehicle laminated glass 210 is arranged with respect to the image unit 31 in a positional relationship of 56 ° that forms a Brewster angle.
The image unit 31 irradiates the projected light vibrating in the X-axis direction vertically upward, and the viewer 35 observes the virtual image displayed on the fourth main surface 124. The viewpoint of the viewer and the height of the laminated glass for the vehicle are the same.
A tablet is used as the image unit 31, and a white grid image is displayed from the tablet. The tablet is placed directly under the laminated glass for vehicles.
Further, in order to simulate the traveling of the moving body at night, a black background plate 37 is arranged on the other side of the laminated glass 210 for the vehicle in the direction in which the viewer 35 can visually recognize the moving body.

As shown in FIGS. 31 and 32, the front of the viewer was set as the point of position 0 in the X-axis direction as the observation point, and the + 200 mm point and the + 400 mm point were provided on the right side.
In the third embodiment, as shown in FIG. 31, the projection unit is arranged so that the optical axis of the retardation film is 45 ° with respect to the X axis in the front area of the viewer (the point at the position 0 in the X-axis direction). Further, the projection unit was arranged so that the optical axes of the retardation film were 55 ° and 65 ° with respect to the X axis, respectively, at the + 200 mm point and the + 400 mm point, which are the areas diagonally forward to the viewer.
The above experiment was carried out by shifting the positions of the 200 mm × 200 mm square projection portions by 200 mm, and arranging the projection portions so that the optical axis of the retardation film was tilted by further tilting the projection portion.
In Comparative Example 3, as shown in FIG. 32, the projection unit was arranged so that the optical axis of the retardation film was 45 ° with respect to the X axis at all observation points.

FIG. 33 is a photograph showing a virtual image visually recognized in Example 3 and Comparative Example 3.
Comparing the two at the same distance from the viewer, it was confirmed that in Example 3, the generation of the double image was suppressed at the +200 mm point and the +400 mm point, which correspond to the diagonally forward region of the viewer.
On the other hand, in Comparative Example 3, a double image extending in the lateral direction was observed at these points.

Subsequently, the experimental results for the case where the diagonally forward region of the viewer is on the left side of the viewer are shown.
FIG. 34 is a diagram schematically showing the experimental system in Example 4, and FIG. 35 is a diagram schematically showing the experimental system in Comparative Example 4. The experimental method is the same as in Example 3.
As shown in FIGS. 34 and 35, the front of the viewer is the point 0 in the X-axis direction as the observation point, and the -100 mm point, the -200 mm point, the -300 mm point, the -400 mm point, and the -500 mm point are on the left side. Provided.
As shown in FIG. 34, in the fourth embodiment, the optical axis of the retardation film is set to 45 ° with respect to the X axis in the viewer front region (position 0 in the X-axis direction), and the viewer diagonally forward region. At -100 mm point, -200 mm point, -300 mm point, -400 mm point, and -500 mm, the optical axes of the retardation film are 40 °, 35 °, 30 °, 25 °, and 20 ° with respect to the X axis, respectively. I did.
As shown in FIG. 35, in Comparative Example 4, the optical axis of the retardation film was set to 45 ° with respect to the X axis at all observation points.

FIG. 36 is a photograph showing a virtual image visually recognized in Example 4 and Comparative Example 4.
When the distances from the viewers are compared at the same position, the generation of double images is suppressed at the -100 mm point, -200 mm point, -300 mm point, -400 mm point, and -500 mm, which correspond to the diagonally forward region of the viewer in the fourth embodiment. I was able to confirm that.
On the other hand, in Comparative Example 4, a double image extending in the lateral direction was observed especially at the -300 mm point, the -400 mm point, and the -500 mm point.

Provided is a HUD device capable of suppressing the generation of a double image when a viewer visually recognizes an image displayed in a region near the outer periphery of the windshield surface of a vehicle such as an automobile or in the central region of the windshield surface from an angle. can do.

This application applies to Japanese Patent Application No. 2020-022342 filed on February 13, 2020, Japanese Patent Application No. 2020-0279220 filed on February 21, 2020, and August 24, 2020. Based on the applied Japanese patent application 2020-140713, it claims priority based on the Paris Convention or the laws and regulations of the transitioning country. The entire content of the application is incorporated herein by reference in its entirety.

1 First HUD device 2 Second HUD device 3 Third HUD device 4

Fourth HUD device

10, 210 Laminated glass for vehicles 11 First glass plate 12 Second glass plate 20 Vehicle 31 Image unit 32 Light emitting point 33 Reflection point 34 Viewpoint 35 Viewer 35D Driver (viewer)
35P passenger (visual person)
36

Polarized sunglasses

40, 60 Projected light 41 Projected light after passing through the

polarized part

42, 241 Optical path based on the reflected image formed on the fourth main surface 61 Projected light after passing through the

polarized part

62, 261 First

main Optical paths

81, 81L, 81R, 81D, 81P, 82, 82L, 82R, 82D, 82P based on the reflection image formed on the

surface Polarizing parts

100, 201, 202 Phase difference film 111 First main surface 112 Second main surface 123 Third main surface 124 Fourth main surface 240 Projected light whose vibration direction is the

X-axis direction

250, 250 ′ Visualist front area 251 of the second embodiment Right peripheral area (viewer oblique front area of the second embodiment)
252, 252'Left peripheral area (viewer diagonally forward area of the second embodiment)
260 Projected light whose vibration direction is parallel to the YZ plane 270 Side glass 271

Right expansion region

412, 421, 421C, 421L, 421R Virtual image (virtual image on the extension of the optical path based on the reflection image formed on the fourth main surface) )
612, 621, 621C, 621L, 621R Virtual image (virtual image on the extension of the optical path based on the reflection image formed on the first main surface)

Claims

A head-up display device mounted on a moving body that allows a viewer who is an occupant of the moving body to recognize a virtual image based on a reflected image at a projection unit of projected light.
The X-axis is the direction horizontal to the ground and orthogonal to the traveling direction when the moving body advances, the Y-axis is horizontal to the ground and the traveling direction when the moving body advances, and the Z-axis is the direction perpendicular to the ground. ,
When the plane having the viewpoint of the viewer, the emission point of the projected light, and the reflection point which is the point at which the projected light is reflected is defined as the incident surface.
The head-up display device is
The image unit that irradiates the projected light and
A polarizing unit provided between the image unit and the projection unit to transmit light contained in the projection light that vibrates in a specific direction.
The projection unit, which projects the projected light transmitted through the polarization unit, is provided.
The projection unit is a laminated glass arranged in the order of a second glass plate, a retardation film, and a first glass plate from the indoor side, which is the incident side of the projected light, to the outdoor side.
It has a viewer front region that is the front of the viewer, and a viewer oblique front region that is a region farther than the viewer front region along any direction in the X-axis direction.
The projected light is projected onto at least the area diagonally forward to the viewer.
When the X-axis when the projection unit is viewed from the viewer is 0 ° and the plane along the retardation film is the projection plane,
The retardation film has an optical axis inclined by θ r with respect to the X axis on the projection surface, and changes the vibration direction of the projected light incident on the projection surface by the optical axis.
A head-up display device characterized in that the specific direction is a direction parallel to the incident surface.
The head-up display device according to claim 1, wherein the viewer observes a virtual image based on a reflected image formed on a side surface other than the indoor side surface of the second glass plate.
The head-up display device according to claim 1, wherein the viewer observes a virtual image based on a reflected image formed on the outdoor surface of the first glass plate.
A head-up display device mounted on a moving body that allows a viewer who is an occupant of the moving body to recognize a virtual image based on a reflected image at a projection unit of projected light.
The X-axis is the direction horizontal to the ground and orthogonal to the traveling direction when the moving body advances, the Y-axis is horizontal to the ground and the traveling direction when the moving body advances, and the Z-axis is the direction perpendicular to the ground. ,
When the plane having the viewpoint of the viewer, the emission point of the projected light, and the reflection point which is the point at which the projected light is reflected is defined as the incident surface.
The head-up display device is
The image unit that irradiates the projected light and
A polarizing unit provided between the image unit and the projection unit to transmit light contained in the projection light that vibrates in a specific direction.
The projection unit, which projects the projected light transmitted through the polarization unit, is provided.
The projection unit is a laminated glass arranged in the order of a second glass plate, a retardation film, and a first glass plate from the indoor side, which is the incident side of the projected light, to the outdoor side.
It has a viewer front region that is the front of the viewer, and a viewer oblique front region that is a region farther than the viewer front region along any direction in the X-axis direction.
The projected light is projected onto at least the area diagonally forward to the viewer.
When the X-axis when the projection unit is viewed from the viewer is 0 ° and the plane along the retardation film is the projection plane,
The retardation film has an optical axis inclined by θ r with respect to the X axis on the projection surface, and the angle formed by the vibration direction θ α of the projected light incident on the projection surface and the optical axis is dθ. In this case, the vibration direction of the incident projected light is rotated by 2dθ.
The head-up display device is characterized in that the vibration direction θ α is a direction of 2 θ r − θ p on the projection surface when the angle of the incident surface with respect to the X axis on the projection surface is θ p.
The head-up display device according to claim 4, wherein the viewer observes a virtual image based on a reflected image formed on the indoor side surface of the second glass plate.
There are multiple viewers,
For each of the viewers, the polarizing portion is provided between the image unit and the projection unit, and each of the viewers has each incident surface which is an incident surface provided for each viewer.
The head-up display device according to any one of claims 1 to 5, wherein each of the polarizing portions transmits projected light that vibrates in the specific direction corresponding to each incident surface.
The polarizing portion has a transmission axis in which the vibration direction of the transmitted projected light is the specific direction.
The head-up display device according to claim 6, wherein the directions of the transmission axes are different from each other.
The projected light is projected onto the central region, which is between the front area of each of the plurality of viewers and corresponds to the diagonally forward region of each of the plurality of viewers. The head-up display device according to claim 7.
In the projection unit, the projection position on which the projected light is projected can be changed.
The head-up display according to claim 1 to 8, wherein the polarizing portion is movable and the vibration direction of the light transmitted through the polarizing portion can be changed in response to a change in the incident surface accompanying the change in the projection position. Device.
A head-up display system mounted on a moving body that allows a viewer who is an occupant of the moving body to visually recognize a virtual image based on a reflected image at a projection unit of projected light.
The X-axis is the direction horizontal to the ground and orthogonal to the traveling direction when the moving body advances, the Y-axis is horizontal to the ground and the traveling direction when the moving body advances, and the Z-axis is the direction perpendicular to the ground. ,
When the plane having the viewpoint of the viewer, the emission point of the projected light, and the reflection point which is the point at which the projected light is reflected is defined as the incident surface.
The head-up display system
The image unit that irradiates the projected light and
A polarizing unit provided between the image unit and the projection unit to transmit light contained in the projection light that vibrates in a specific direction.
The projection unit on which the projected light is projected is provided.
The projection unit is a laminated glass arranged in the order of a second glass plate, a retardation film, and a first glass plate from the indoor side, which is the incident side of the projected light, to the outdoor side.
It has a viewer front region that is the front of the viewer, and a viewer oblique front region that is a region farther than the viewer front region along any direction in the X-axis direction.
The projected light is projected onto at least the area diagonally forward to the viewer.
When the X-axis when the projection unit is viewed from the viewer is 0 ° and the plane along the retardation film is the projection plane,
The retardation film has an optical axis inclined by θ r with respect to the X axis on the projection surface, and changes the vibration direction of the projected light incident on the projection surface by the optical axis.
The polarizing portion is movable, and the following (A) and (B) can be switched by changing the vibration direction of the light transmitted through the polarizing portion.
(A) The vibration direction of the light incident on the second glass plate is set to be a direction parallel to the incident surface.
(B) the retardation film, when a dθ the angle vibration direction theta alpha and said optical axis of said projection light incident on the projection plane, thereby 2dθ rotational oscillation direction of the projection light incident Assuming that, the vibration direction of the light transmitted through the second glass plate is the direction of 2θ r − θ p on the projection surface when the angle of the incident surface with respect to the X axis on the projection surface is θ p. To be.
In the projection unit, the projection position on which the projected light is projected can be changed.
The head-up display system according to claim 10, wherein the polarizing portion is movable and the vibration direction of the projected light transmitted through the polarizing portion can be changed in response to a change in the incident surface accompanying the change in the projection position. ..
A head-up display device mounted on a moving body that allows a viewer who is an occupant of the moving body to visually recognize a virtual image based on a reflected image at a projection unit of projected light.
The X-axis is the direction horizontal to the ground and orthogonal to the traveling direction when the moving body advances, the Y-axis is horizontal to the ground and the traveling direction when the moving body advances, and the Z-axis is the direction perpendicular to the ground. ,
When the plane having the viewpoint of the viewer, the emission point of the projected light, and the reflection point which is the point at which the projected light is reflected is defined as the incident surface.
The head-up display device is
An image unit that irradiates the projected light whose vibration direction is the X-axis direction, and
A projection unit on which the projected light is projected is provided.
The projection unit is arranged in the traveling direction when the moving body moves forward, and is arranged on the incident side of the projected light and the emitting side of the projected light. It is composed of a laminated glass provided with a first glass plate, a retardation film arranged between the second glass plate, and the first glass plate.
The first glass plate includes a first main surface exposed to the outdoor side and a second main surface opposite to the first main surface.
The second glass plate includes a fourth main surface exposed to the indoor side and a third main surface opposite to the fourth main surface.
By making the projected light incident on the retardation film, the vibration direction of the projected light can be converted into a direction parallel to the incident surface.
The projection unit has a viewer front region that is the front of the viewer and a viewer oblique front region that is a region that is far from the viewer front region along any direction in the X-axis direction. death,
When the viewer sees the reflected image formed in the front area of the viewer, the retardation film arranged in the front area of the viewer is a plane parallel to the fourth main surface of the retardation film. The optical axis is 45 ° ± 5 ° with respect to the X axis.
When the viewer sees the reflected image formed in the viewer obliquely front region, the retardation film arranged in the viewer diagonally front region has the phase difference in a plane parallel to the fourth main surface. The optical axis of the film is tilted in a direction that deviates from the X axis by 45 ° ± 5 °.
The imaginary image is based on a reflection image formed on the fourth main surface of the second glass plate.
In both the front area of the viewer and the diagonally front area of the viewer, the light emitted from the first main surface of the first glass plate is the projected light that vibrates mainly in a direction parallel to the incident surface. A head-up display device characterized by being.
A head-up display device mounted on a moving body that allows a viewer who is an occupant of the moving body to visually recognize a virtual image based on a reflected image at a projection unit of projected light.
The X-axis is the direction horizontal to the ground and orthogonal to the traveling direction when the moving body advances, the Y-axis is horizontal to the ground and the traveling direction when the moving body advances, and the Z-axis is the direction perpendicular to the ground. ,
When the plane having the viewpoint of the viewer, the emission point of the projected light, and the reflection point which is the point at which the projected light is reflected is defined as the incident surface.
The head-up display device is
The image unit that irradiates the projected light whose vibration direction is parallel to the YZ plane, and
A projection unit on which the projected light is projected is provided.
The projection unit is arranged in the traveling direction when the moving body moves forward, and is arranged on the incident side of the projected light and the emitting side of the projected light. It is composed of a laminated glass provided with a first glass plate, a retardation film arranged between the second glass plate, and the first glass plate.
The first glass plate includes a first main surface exposed to the outdoor side and a second main surface opposite to the first main surface.
The second glass plate includes a fourth main surface exposed to the indoor side and a third main surface opposite to the fourth main surface.
By making the projected light incident on the retardation film, the vibration direction of the projected light can be converted into a direction perpendicular to the incident surface.
The projection unit has a viewer front region that is the front of the viewer and a viewer oblique front region that is a region that is far from the viewer front region along any direction in the X-axis direction. death,
When the viewer sees the reflected image formed in the front area of the viewer, the retardation film arranged in the front area of the viewer is a plane parallel to the fourth main surface of the retardation film. The optical axis is 45 ° ± 5 ° with respect to the X axis.
When the viewer sees the reflected image formed in the viewer obliquely front region, the retardation film arranged in the viewer diagonally front region has the phase difference in a plane parallel to the fourth main surface. The optical axis of the film is tilted in a direction that deviates from the X axis by 45 ° ± 5 °.
The imaginary image is based on a reflection image formed on the first main surface of the first glass plate.
In both the front area of the viewer and the diagonally front area of the viewer, the light reflected by the first main surface of the first glass plate is the projected light that vibrates mainly in the direction perpendicular to the incident surface. A head-up display device, characterized in that it is.
In the right peripheral region located on the right side of the visual visual front region and the left peripheral region located on the left side of the visual visual front region, the optical axis of the retardation film is the X-axis in the visible diagonal front region. The head-up display device according to claim 12 or 13, wherein the direction of deviation from 45 ° ± 5 ° is opposite to that of the device.
The head-up display device according to any one of claims 12 to 14, wherein the change in the inclination of the retardation film in the direction of the optical axis in the diagonally forward region of the viewer is continuously made along the X-axis direction.
The head-up display device according to any one of claims 12 to 14, wherein the change in the inclination of the retardation film in the direction of the optical axis in the area diagonally forward to the viewer is discontinuous along the X-axis direction. ..
An integral retardation film having a vertical axis in the vertical direction and a horizontal axis in the horizontal direction.
At a plurality of points along the vertical axis, the angle formed by the optical axis of the retardation film and the horizontal axis is constant.
A retardation film characterized in that the angle formed by the optical axis of the retardation film and the horizontal axis changes with a constant tendency along the horizontal axis direction.
The retardation film according to claim 17, wherein the angle formed by the optical axis of the retardation film and the horizontal axis continuously changes along the horizontal axis direction.
The retardation film according to claim 17, wherein the angle formed by the optical axis of the retardation film and the horizontal axis changes discontinuously along the horizontal axis direction.
A laminated glass for a vehicle including a first glass plate, a second glass plate, and a retardation film arranged between the first glass plate and the second glass plate.
A laminated glass for a vehicle, wherein the retardation film is the retardation film according to any one of claims 17 to 19.
A head-up display system mounted on a moving body that allows a viewer who is an occupant of the moving body to visually recognize a virtual image based on a reflected image at a projection unit of projected light.
The X-axis is the direction horizontal to the ground and orthogonal to the traveling direction when the moving body advances, the Y-axis is horizontal to the ground and the traveling direction when the moving body advances, and the Z-axis is the direction perpendicular to the ground. ,
When the plane having the viewpoint of the viewer, the emission point of the projected light, and the reflection point which is the point at which the projected light is reflected is defined as the incident surface.
The head-up display system
The image unit that irradiates the projected light and
A projection unit on which the projected light is projected is provided.
The projection unit is arranged in the traveling direction when the moving body moves forward, and is arranged on the incident side of the projected light and the emitting side of the projected light. It is composed of a laminated glass provided with a first glass plate, a retardation film arranged between the second glass plate, and the first glass plate.
The first glass plate includes a first main surface exposed to the outdoor side and a second main surface opposite to the first main surface.
The second glass plate includes a fourth main surface exposed to the indoor side and a third main surface opposite to the fourth main surface.
By making the projected light incident on the retardation film, the vibration direction of the projected light can be converted into a direction parallel to or perpendicular to the incident surface.
The projection unit has a viewer front region that is the front of the viewer and a viewer oblique front region that is a region that is far from the viewer front region along any direction in the X-axis direction. death,
When the viewer sees the reflected image formed in the front area of the viewer, the retardation film arranged in the front area of the viewer is a plane parallel to the fourth main surface of the retardation film. The optical axis is 45 ° ± 5 ° with respect to the X axis.
When the viewer sees the reflected image formed in the viewer obliquely front region, the retardation film arranged in the viewer diagonally front region has the phase difference in a plane parallel to the fourth main surface. The optical axis of the film is tilted in a direction that deviates from the X axis by 45 ° ± 5 °.
The image unit can switch between the first projected light whose vibration direction is the X-axis direction and the second projected light whose vibration direction is parallel to the YZ plane.
When the viewer visually recognizes the virtual image without passing through the polarizing plate, the first projected light is irradiated from the image unit, and the virtual image is formed on the fourth main surface of the second glass plate. Based on the reflected image, the light emitted from the first main surface of the first glass plate is mainly in the direction parallel to the incident surface in both the viewer front region and the viewer oblique front region. It is a vibrating projected light,
When the viewer visually recognizes the virtual image through the polarizing plate, the second projected light is irradiated from the image unit, and the virtual image is a reflection formed on the first main surface of the first glass plate. Based on the image, the light reflected by the first main surface of the first glass plate vibrates mainly in the direction perpendicular to the incident surface in both the viewer front region and the viewer oblique front region. A head-up display system characterized by being projected light.